U.S. patent application number 15/514715 was filed with the patent office on 2017-07-27 for compositions comprising beta mannanase and methods of use.
The applicant listed for this patent is Danisco US Inc.. Invention is credited to Steven Le, Zhen Qian.
Application Number | 20170211052 15/514715 |
Document ID | / |
Family ID | 54291712 |
Filed Date | 2017-07-27 |
United States Patent
Application |
20170211052 |
Kind Code |
A1 |
Le; Steven ; et al. |
July 27, 2017 |
COMPOSITIONS COMPRISING BETA MANNANASE AND METHODS OF USE
Abstract
The present compositions and methods relate to a beta-mannanase
from Mahella australiensis, polynucleotides encoding the
beta-mannanase, and methods of make and/or use thereof.
Formulations containing the beta-mannanase are suitable for use in
hydrolyzing lignocellulosic biomass substrates, especially those
comprising a measurable level of galactoglucomannan (GGM) and/or
glucomannan (GM).
Inventors: |
Le; Steven; (Palo Alto,
CA) ; Qian; Zhen; (Palo Alto, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Danisco US Inc. |
Palo Alto |
CA |
US |
|
|
Family ID: |
54291712 |
Appl. No.: |
15/514715 |
Filed: |
September 30, 2015 |
PCT Filed: |
September 30, 2015 |
PCT NO: |
PCT/US2015/053147 |
371 Date: |
March 27, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C12P 19/02 20130101;
C12Y 302/01025 20130101; C12N 9/2491 20130101; C12P 19/14
20130101 |
International
Class: |
C12N 9/24 20060101
C12N009/24; C12P 19/14 20060101 C12P019/14; C12P 19/02 20060101
C12P019/02 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 30, 2014 |
CN |
PCT/CN2014/087860 |
Claims
1-13. (canceled)
14. An enzyme composition comprising a recombinant polypeptide
comprising an amino acid sequence that is at least 55% identical to
the amino acid sequence of SEQ ID NO:2 or SEQ ID NO:3, wherein the
polypeptide has beta-mannanase activity, and further comprising one
or more cellulases.
15. The enzyme composition of claim 14, wherein the one or more
cellulases are selected from one or more beta-glucosidases, one or
more cellobiohydrolases, and one or more endoglucanases.
16. An enzyme composition comprising a recombinant polypeptide
comprising an amino acid sequence that is at least 55% identical to
the amino acid sequence of SEQ ID NO:2 or SEQ ID NO:3, wherein the
polypeptide has beta-mannanase activity, and further comprising one
or more other hemicellulases.
17. The enzyme composition of claim 16, wherein the one or more
other hemicellulases are selected from one or more other
beta-mannanases, one or more one or more xylanases, one or more
beta-xylosidases, and one or more L-arabinofuranosidases.
18-21. (canceled)
22. A host cell comprising an expression vector comprising a
nucleic acid in operable combination with a regulatory sequence,
the nucleic acid encoding a recombinant polypeptide comprising an
amino acid sequence that is at least 55% identical to the amino
acid sequence of SEQ ID NO:2 or SEQ ID NO:3, wherein the
polypeptide has beta-mannanase activity.
23. The host cell of claim 22, wherein the host cell is a bacterial
cell or a fungal cell.
24. A composition comprising the host cell of claim 22 and a
culture medium.
25. A method of producing a beta-mannanase, comprising: culturing
the host cell of claim 22 in a culture medium, under suitable
conditions to produce the beta-mannanase.
26. A composition comprising the beta-mannanase produced in
accordance with the method of claim 25 in supernatant of the
culture medium.
27. A method for hydrolyzing a lignocellulosic biomass substrate,
comprising: contacting the lignocellulosic biomass substrate with a
recombinant polypeptide comprising an amino acid sequence that is
at least 55% identical to the amino acid sequence of SEQ ID NO:2 or
SEQ ID NO:3, wherein the polypeptide has beta-mannanase activity,
to yield glucose and other sugars.
28. The method of claim 27, wherein the lignocellulosic biomass
substrate comprises up to about 20 wt. %, up to about 15%, or up to
about 10 wt. % of galactoglucomannan and/or glucomannan.
29. A composition comprising a recombinant polypeptide comprising
an amino acid sequence that is at least 55% identical to the amino
acid sequence of SEQ ID NO:2 or SEQ ID NO:3, wherein the
polypeptide has beta-mannanase activity, and a lignocellulosic
biomass substrate.
30. The composition of claim 29, wherein the lignocellulosic
biomass substrate comprises up to about 20 wt. %, or up to about 15
wt. %, or up to about 10 wt. % of galactoglucomannan and/or
glucomannan.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority from PCT
Application No. PCT/CN2014/087860, filed in the China Intellectual
Property Office on Sep. 30, 2014, the entirety of which is herein
incorporated by reference.
FIELD OF THE INVENTION
[0002] The present compositions and methods relates to a
beta-mannanase derived from Mahella australlensis, polynucleotides
encoding the beta-mannanase, and methods for the production and use
thereof. Formulations containing the recombinant beta-mannanase
have a wide variety of uses, for instance, in hydrolyzing certain
soft-wood type lignocellulosic materials and/or lignocellulosic
biomass substrates comprising galactoglucomannan (GGM) and/or
glucomannan (GM).
REFERENCE TO SEQUENCE LISTING SUBMITTED ELECTRONICALLY
[0003] The content of the electronically submitted sequence listing
in ASCII text file (Name:
20150930_NB40687WOPCT2_SequenceListing_ST25.txt; Size: 41,087
bytes, and Date of Creation: Sep. 29, 2015) filed with the
application is incorporated herein by reference in its
entirety.
BACKGROUND
[0004] Cellulose and hemicellulose are the most abundant plant
materials produced by photosynthesis. They can be degraded and used
as an energy source by numerous microorganisms (e.g., bacteria,
yeast and fungi) that produce extracellular enzymes capable of
hydrolysis of the polymeric substrates to monomeric sugars (Aro et
al., (2001) J. Biol. Chem., 276: 24309-24314). As the limits of
non-renewable resources approach, the potential of cellulose to
become a major renewable energy resource is enormous (Krishna et
al., (2001) Bioresource Tech., 77: 193-196). The effective
utilization of cellulose through biological processes is one
approach to overcoming the shortage of foods, feeds, and fuels
(Ohmiya et al., (1997) Biotechnol. Gen. Engineer Rev., 14:
365-414).
[0005] Most of the enzymatic hydrolysis of lignocellulosic biomass
materials focus on cellulases, which are enzymes that hydrolyze
cellulose (comprising beta-1,4-glucan or beta D-glucosidic
linkages) resulting in the formation of glucose, cellobiose,
cellooligosaccharides, and the like. Cellulases have been
traditionally divided into three major classes: endoglucanases (EC
3.2.1.4) ("EG"), exoglucanases or cellobiohydrolases (EC 3.2.1.91)
("CBH") and beta-glucosidases ([beta]-D-glucoside glucohydrolase;
EC 3.2.1.21) ("BG") (Knowles et al., (1987) TIBTECH 5: 255-261; and
Schulein, (1988) Methods Enzymol., 160: 234-243). Endoglucanases
act mainly on the amorphous parts of the cellulose fiber, whereas
cellobiohydrolases are also able to degrade crystalline cellulose
(Nevalainen and Penttila, (1995) Mycota, 303-319). Thus, the
presence of a cellobiohydrolase in a cellulase system is required
for efficient solubilization of crystalline cellulose (Suurnakki et
al., (2000) Cellulose, 7: 189-209). Beta-glucosidase acts to
liberate D-glucose units from cellobiose, cello-oligosaccharides,
and other glucosides (Freer, (1993) J. Biol. Chem., 268:
9337-9342).
[0006] In order to obtain useful fermentable sugars from
lignocellulosic biomass materials, however, the lignin will
typically first need to be permeabilized, for example, by various
pretreatment methods, and the hemicellulose disrupted to allow
access to the cellulose by the cellulases. Hemicelluloses have a
complex chemical structure and their main chains are composed of
mannans, xylans and galactans. Mannan-type polysaccharides are
found in a variety of plants and plant tissues, for example, in
seeds, roots, bulbs and tubers of plants. Such saccharides may
include mannans, galactomannas and glucomannans, and they typically
containing linear and interspersed chains of linear beta-1,4-linked
mannose units and/or galactose units. Most types of mannans are not
soluble in water, forming the hardness characteristic of certain
plant tissues like palm kernels and ivory nuts. Galactomannas, on
the other hand, tend to be water soluble and are found in the seed
endosperm of leguminous plants, and are thought to help with
retention of water in those seeds.
[0007] Enzymatic hydrolysis of the complex lignocellulosic
structure and rather recalcitrant plant cell walls involves the
concerted and/or tandem actions of a number of different
endo-acting and exo-acting enzymes (e.g., cellulases and
hemicellulases). Beta-xylanases and beta-mannanases are endo-acting
enzymes, beta-mannosidase, beta-glucosidase and
alpha-galactosidases are exo-acting enzymes. To disrupt the
hemicelulose, xylanases together with other accessory proteins
(non-limiting examples of which include
L-.alpha.-arabinofuranosidases, feruloyl and acetylxylan esterases,
glucuronidases, and .beta.-xylosidases) can be applied.
[0008] Endo-1,4-beta-D-mannanases (E.C. 3.2.1.78) catalyzes the
random hydrolysis of beta-1,4-mannosidic linkages in the main chain
of mannan, galactomannanan, glucomannan, and galactoglucomannan,
releasing short and long-chain oligomannosides. The short-chain
oligomannosides may include mannobiose and mannotriose, although
sometimes may also include some mannose. These can be further
hydrolyzed by beta-mannosidases (E.C.3.2.1.25). In addition, the
side-chain sugars of heteropolysaccharides can be further
hydrolyzed, for example, to completion, by alpha galactosidase,
beta-glucosidase, and/or by acetylmannan esterases. Puls J., (1997)
Macromol. Symp. 120:183-196.
[0009] Beta-mannanases have been isolated from bacteria, fungi,
plants and animals. See, Araujo A. et al., (1990) J. App.
Bacteriol. 68:253-261; Dutta S. et al., (1997) Plant Physiol.
113:155-161; Puchar V. et al., (2004) Biochim. Biophys. Acta
1674:239-250. Genes encoding these enzymes from a number of
organisms have also been cloned and sequenced, many if not all have
been classified also as members of glycosyl hydrolase (GH) family 5
or 26, based on their sequences. See, e.g., Bewley D. J., (1997)
Planta 203:454-459; Halstead J. R. et al., (2000) FEMS Microl.
Lett. 192:197-203; Xu B. et al., (2002) Eur. J. Biochem.
269:1753-1760; Henrissat, B. (1991) Biochem. J. 280:309-316.
Although most beta-mannanases are secreted by the organisms from
which they are originated, some are known to be associated with the
cells. From a given organism there may be more than one mannanases
with different isoelectric points derived from different genes or
different products of the same genes, which fact is thought to be
an indication of the importance of these enzymes.
[0010] Beta-mannanases have been used in commercially applications
in, for example, industries such as the paper and pulp industry,
foodstuff and feed industry, pharmaceutical industry and energy
industry. Lee J T., et al., (2003) Poult. Sci. 82:1925-1931;
McCutchen M. C., et al., (1996) Biotechnol. Bioeng. 52:332-339;
Suurnakki A., et al., (1997) Adv. Biochem. Eng. Biotechnol.,
57:261-287. Depending on the microorganisms from which the
mannanases are derived, however, different beta-mannanases may have
different properties and activity profiles that may make them more
suitable for one or more industrial applications but not for
others. The hydrolysis of lignocellulosic biomass substrates,
especially those from plant sources, is notoriously difficult,
accordingly few if any mannanases that have been found to be useful
in other industrial applications have been utilized to hydrolyze
lignocellulosic materials.
[0011] Thus there exists a need to identify mannanases and/or
compositions comprising such enzymes that are effective at and
capable of, in conjunction with commercial, newly identified, or
engineered cellulases and other hemicellulases, converting a wide
variety of plant-based and/or other cellulosic or hemicellulosic
materials into fermentable sugars with sufficient or improved
efficacy, improved fermentable sugar yields, and/or improved
capacity to act on a greater variety of cellulosic feedstock. The
production of new mannanases using engineered microbes is also
important and desirable because these are means through which
enzymes can be cost-effectively made.
SUMMARY OF THE INVENTION
[0012] One aspect of the present compositions and methods is the
application or use of a highly active beta-mannanase isolated from
the bacterial species Mahella australiensis strain, to hydrolyze a
lignocellulosic biomass substrate. The herein described sequence of
SEQ ID NO:2 was submitted to and published in 2011 by the National
Center for Biotechnology Information, U.S. National Library of
Medicine (NCBI) with the Accession YP_004463131.1 or AEE96309.1,
which has been designated to be a hypothetical cellulose-binding
glycosyl hydrolase family (GH) 5 proteins, derived from the Mahella
australiensis strain 50-1 BON ("MauMan1" herein). To date this
enzyme has not been recombinantly expressed, expressed in an
industrially or commercially relevant amount, or applied in
industrial applications. MauMan1 polypeptides have not been
expressed by an engineered microorganism. Nor have they been
coexpressed with, or included in a composition with, one or more
cellulase genes and/or one or more hemicellulases.
[0013] Therefore an aspect of the present invention is the
discovery that polypeptides having at least 55% (e.g., at least
55%, at last 60%, at least 65%, at least 70%, at least 75%, at
least 80%, at least 85%, at least 90%, at least 91%, at least 91%,
at least 92%, at least 93%, at least 94%, at least 95%, at least
96%, at least 97%, at least 98%, at least 99% or higher) identity
to SEQ ID NO:2, or to the mature sequence of SEQ ID NO:3, which is
residues 28-512 of SEQ ID NO:2, have beta-mannanase activity.
Another aspect of the present invention is the discovery that, when
such a polypeptide is combined with one or more cellulases and/or
one or more other hemicellulases confer improved capacity of that
composition or mixture to hydrolyze of lignocellulosic biomass
substrates. Such improvements include, for example, one or more of
the properties selected from: an increased glucan conversion, an
increased glucose yield from a given biomass substrate, an
increased xylan conversion, an increased xylose yield, an increased
total soluble sugar yield from a given biomass substrate, a more
rapid liquefaction of a given biomass substrate at a solids level,
and a more rapid viscosity reduction of a biomass substrate at a
solids level. Improvements also may include the surprising finding
that such a polypeptide can be used to boost the cellulosic biomass
conversion and hydrolysis when in combination with a cellulase
mixture or composition, which optionally further comprises one or
more other hemicellulase. The resulting mixture comprising the
MauMan1 polypeptide has improved hydrolysis performance as compared
to a counterpart mixture having all the other enzymes at the same
concentrations/proportion/amounts, but without the MauMan1. In some
embodiments, the MauMan1 polypeptides can substitute, for example,
for up to about 20 wt. % (e.g., up to about 20 wt. %, up to about
18 wt. %, up to about 16 wt. %, up to about 14 wt. %, up to about
12 wt. %, up to about 10 wt. %, up to about 8 wt. %, up to about 5
wt. %, etc) of a cellulase mixture or composition, and the
substituted composition when used to hydrolyze a given
lignocellulosic biomass substrate will retain its capacity and
hydrolysis performance, or even have improved hydrolysis (e.g.,
higher glucan and/or xylan conversion, higher production of total
sugars, faster liquefaction, and/or improved viscosity reduction)
than a un-substituted counterpart cellulase mixture or composition
of otherwise the same enzyme composition and the same total
protein.
[0014] An aspect of the present composition and methods pertains to
a beta-mannanase polypeptide of cellulose binding protein derived
from Mahella australiensis, or a suitable variant thereof having
beta-mannanase activity, referred to herein as "MauMan1" or a
"MauMan1 polypeptide," nucleic acids encoding the same,
compositions comprising the same, and methods of producing and
applying the beta-mannanase polypeptides and compositions
comprising thereof in hydrolyzing or converting lignocellulosic
biomass into soluble, fermentable sugars. Particularly suitable
lignocellulosic biomass materials are those that contain
galactoglucomannan (GGM) and/or glucomannan (GM). Such fermentable
sugars can then be converted into cellulosic ethanol, fuels, and
other biochemicals and useful products. In certain embodiments, the
beta-mannanase polypeptides, when combined with an enzyme mixture
comprising at least one cellulase or at least one other
hemicellulase, or with an enzyme mixture comprising at least one
cellulase and at least one other hemicellulase, resulted in an
enzyme mixture that is capable of increased or enhanced capacity to
hydrolyze a lignocellulosic biomass material, as compared to, for
example, other beta-mannanases from various microbes, which have
similar pH optimum and/or similar temperature optimum.
[0015] Such increased or enhanced capacity to hydrolyze a
lignocellulosic biomass material is reflected, for example, in
substantially increased production of not only total soluble
sugars, but surprisingly also increased production of glucose
(reflecting a higher glucan conversion) and/or increased production
of xylose (reflecting a higher xylan conversion), produced by
enzymatic hydrolysis of a given lignocellulosic biomass substrate
pretreated in a certain way.
[0016] The increased or enhanced capacity to hydrolyze a
lignocellulosic biomass material can also be reflected in the
desirable capacity of such an enzyme composition to improve or
accelerate liquefaction and/or reduce viscosity of the pretreated
biomass material. Such a viscosity/liquefaction benefit is the most
prominent if a high solids level of the biomass material is used as
a substrate. The viscosity/liquefaction benefits are also
substantial and important when the enzyme composition/mixture is
used to break down or hydrolyze a woody biomass, which tends to be
highly fibrous and recalcitrant, making for particularly viscous
feedstocks.
[0017] The increased or enhanced capacity to hydrolyze a
lignocellulosic biomass allows the substitution of up to about 20
wt. % (e.g., up to about 20 wt. %, up to about 18 wt. %, up to
about 16 wt. %, up to about 14 wt. %, up to about 12 wt. %, up to
about 10 wt. %, up to about 8 wt. %, up to about 5 wt. %, etc) of
any given cellulase composition, which optionally comprises one or
more other hemicellulases, with a MauMan1 polypeptide, thereby
reducing the amount of cellulase composition and the enzymes
therein used to hydrolyze a given substrate without sacrificing
performance. Indeed, the hydrolysis performance may even be
improved using the substituted composition. Reducing the amount of
cellulase composition as well as the amount of enzymes therein
required to hydrolyze or saccharify a lignocellulosic biomass
results in a substantial cost-savings to produce a cellulosic
sugar, which can then be made into ethanol or other down-stream
valuable bio-chemicals and useful products.
[0018] Aspects of the present compositions and methods are drawn to
beta-mannanase derived from Mahella australiensis, referred to
herein as "MauMan1" or "MauMan1 polypeptides," nucleic acids
encoding the same, and methods of producing and employing the
beta-mannanase in various industrially useful applications, for
example, in hydrolyzing or converting lignocellulosic biomass into
soluble, fermentable sugars. Such fermentable sugars can then be
converted into cellulosic ethanol, fuels, and other bio-chemicals
and useful products. As demonstrated herein, MauMan1 polypeptides
as well as compositions comprising MauMan1 polypeptides have
improved performance, when combined with at least one cellulase
and/or at least one other hemicellulase, in hydrolyzing
lignocellulosic biomass substrates, especially those that contain
at least some measurable levels of galactoglucomannan (GGM) and/or
glucomannan (GM), as compared to other beta-mannanases from similar
microorganisms having similar pH optimums and/or temperature
optimums. The improved performance may be that the MauMan1
polypeptides and/or enzyme compositions comprising MauMan1
polypeptides produces increased amounts of total soluble sugars
when used to hydrolyze a lignocellulosic biomass substrate, under
suitable conditions for the enzymatic hydrolysis, when compared to
other microbial beta-mannanases having similar pH optimums and/or
temperature optimums. Surprisingly the MauMan1 polypeptides and/or
the compositions comprising such polypeptides also have improved
glucan conversion and/or improved xylan conversion, as compared to
those other microbial beta-mannanases having similar pH optimums
and/or temperature optimums. The improved performance may
alternatively or also be that the MauMan1 polypeptides and/or
enzyme compositions comprising MauMan1 polypeptides confer rapid
viscosity reduction/liquefaction to the biomass substrate, such
that the overall hydrolysis is improved in not only effectiveness
but also efficiency.
[0019] In some embodiments, a MauMan1 polypeptide is applied
together with, or in the presence of, one or more cellulases in an
enzyme composition to hydrolyze or breakdown a suitable biomass
substrate. The one or more cellulases may be, for example, one or
more beta-glucosidases, cellobiohydrolases, and/or endoglucanases.
For example, the enzyme composition may comprise a MauMan1
polypeptide, a beta-glucosidase, a cellobiohydrolase, and an
endoglucanase. In some embodiments, at least one of the cellulases
is heterologous to the MauMan1, in that at least one of the
cellulases is not derived from a Mahella australiensis. In some
embodiments, at least two among the cellulases are heterologous
from each other.
[0020] In some embodiments, a MauMan1 polypeptide is applied
together with, or in the presence of, one or more other
hemicellulases in an enzyme composition. The one or more other
hemicellulases may be, for example, other mannanases, xylanases,
beta-xylosidases, and/or L-arabinofuranosidases. In some
embodiments, at least one of the other hemicellulases is
heterologous to the MauMan1, in that at least one of the other
hemicellulases, which may be selected from one or more other
mannanases, xylanases, beta-xylosidases, and/or
L-arabinofuranosidases, is not derived from a Mahella
australiensis. In certain embodiments, at least two of the other
hemicellulases are heterologous to each other.
[0021] In further embodiments, the MauMan1 polypeptide is applied
together with, or in the presence of, one or more cellulases and
one or more other hemicellulases in an enzyme composition. For
example, the enzyme composition comprises a MauMan1 polypeptide, no
or one or two other mannanases, one or more cellobiohydrolases, one
or more endoglucanases, one or more beta-glucosidases, no or one or
more xylanases, no or one or more beta-xylosidases, and no or one
or more L-arabinofuranosidases.
[0022] In some embodiments, a MauMan1 polypeptide is used to
substitute up to about 20 wt. % (based on total weight of proteins
in a composition) (e.g., up to about 20 wt. %, up to about 18 wt.
%, up to about 16 wt. %, up to about 14 wt. %, up to about 12 wt.
%, up to about 10 wt. %, up to about 8 wt. %, up to about 5 wt. %,
etc) of an enzyme composition comprising one or more cellulases,
optionally also one or more other non-MauMan1 hemicellulases. In
some embodiments, the thus-substituted enzyme composition has
similar or improved saccharification performance as the counterpart
unsubstituted enzyme composition having no MauMan1 present but all
the other cellulases and/or hemicellulases, as well as the same
total weight of proteins in the composition. In some embodiments,
the substituted enzyme composition can produce the same amount of
glucose and/or xylose, or an about 5% higher amount of glucose
and/or xylose, about 7% higher amount of glucose and/or xylose,
about 10% higher amount of glucose and/or xylose, or an even
greater amount of glucose and/or xylose from the same
lignocellulosic biomass substrate, as compared to the
un-substituted counterpart enzyme composition having no MauMan1 but
all the other cellulases and/or hemicellulases, and comprising the
same total weight of proteins in the composition. In some
embodiments, when used to hydrolyze a given lignocellulosic biomass
substrate at a given solids level, the substituted enzyme
composition reduces the viscosity of the biomass substrate by the
same extent or to a higher extent, when compared to the
un-substituted counterpart enzyme composition comprising no MauMan1
but all the other cellulases and/or hemicellulases, and comprising
the same total weight of proteins in the composition.
[0023] In certain embodiments, a MauMan1 polypeptide, or a
composition comprising the MauMan1 polypeptide is applied to a
lignocellulosic biomass substrate or a partially hydrolyzed
lignocellulosic biomass substrate in the presence of an ethanologen
microbe, which is capable of metabolizing the soluble fermentable
sugars produced by the enzymatic hydrolysis of the lignocellulosic
biomass substrate, and converting such sugars into ethanol,
biochemicals or other useful materials. Such a process may be a
strictly sequential process whereby the hydrolysis step occurs
before the fermentation step. Such a process may, alternatively, be
a hybrid process, whereby the hydrolysis step starts first but for
a period overlaps the fermentation step, which starts later. Such a
process may, in a further alternative, be a simultaneous hydrolysis
and fermentation process, whereby the enzymatic hydrolysis of the
biomass substrate occurs while the sugars produced from the
enzymatic hydrolysis are fermented by the ethanologen.
[0024] The MauMan1 polypeptide, for example, may be a part of an
enzyme composition, which is a whole broth product of an engineered
microbe capable of expressing or over-expressing such a polypeptide
under suitable conditions. In certain embodiments, the MauMan1
polypeptide may be genetically engineered to express in a bacterial
host cell, for example, in Escherichia, Bacillus, Lactobacillus,
Pseudomonas, or Streptomyces. In certain embodiments, the MauMan1
polypeptide may be genetically engineered to express in a fungal
host cell, for example, in a host cell of any one of the
filamentous forms of the subdivision Eumycotina. Thus suitable
filamentous fungal host cells may include, without limitation,
cells of Acremonium, Aspergillus, Aureobasidium, Bjerkandera,
Ceriporiopsis, Chrysoporium, Coprinus, Coriolus, Corynascus,
Chaertomium, Cryptococcus, Filobasidium, Fusarium, Gibberella,
Humicola, Magnaporthe, Mucor, Myceliophthora, Mucor,
Neocallimastix, Neurospora, Paecilomyces, Penicillium,
Phanerochaete, Phlebia, Piromyces, Pleurotus, Scytaldium,
Schizophyllum, Sporotrichum, Talaromyces, Thermoascus, Thielavia,
Tolypocladium, Trametes, and Trichoderma.
[0025] The engineered microbe expressing or over-expressing the
MauMan1 polypeptide may also express and/or secrete one or more or
all of one or more cellulases and optionally also one or more other
hemicellulases. The one or more cellulases may be selected from,
for example, one or more endoglucanases, one or more
beta-glucosidases, and/or one or more cellobiohydrolases. The one
or more other hemicellulases may be selected from, for example, one
or more other beta-mannanases, one or more
Alpha-L-arabinofuranosidases, one or more xylanases, and/or one or
more beta-xylosidases. The resulting enzyme mixture comprising the
MauMan1 polypeptide is a "co-expressed enzyme mixture" for the
purpose of this application.
[0026] In another embodiment, the engineered microbe expressing or
over-expressing the MauMan1 polypetpide may be one that is
different from the one or more other microbes expressing one or
more of the cellulases and/or one or more of the other
hemicellulases. The one or more cellulases may be selected from,
for example, one or more endoglucanases, one or more
beta-glucosidases, and/or one or more cellobiohydrolases. The one
or more other hemicellulases may be selected from, for example, one
or more other beta-mannanases, one or more
Alpha-L-arabinofuranosidases, one or more xylanases, and/or one or
more beta-xylosidases. Accordingly the MauMan1 polypeptide can be
combined with one or more cellulases and/or one or more other
hemicellulases to form an enzyme mixture/composition, which is a
"physical mixture" or "admixture" of MauMan1 and other
polypeptides. The improved capacity observable or achievable with
the co-expressed enzyme mixture is also observable or achievable
with the admixture comprising MauMan1.
[0027] As demonstrated herein, MauMan1 polypeptides and
compositions comprising MauMan1 polypeptides have improved efficacy
at conditions under which saccharification and degradation of
lignocellulosic biomass take place. The improved efficacy of an
enzyme composition comprising a MauMan1 polypeptide is shown when
its performance of hydrolyzing a given biomass substrate is
compared to that of an otherwise comparable enzyme composition
comprising certain other microbial beta-mannanases having similar
pH optimums and/or temperature optimums. In certain embodiments,
MauMan1 polypeptides of the compositions and methods herein have at
least about 5% (for example, at least about 5%, at least about 7%,
at least about 10%, at least about 12%, at least about 13%, at
least about 14%, at least about 15%, or more) increased capacity to
hydrolyze a given lignocellulosic biomass substrate, which has
optionally been subject to pretreatment, as compared to a benchmark
GH5 beta-mannanase polypeptide ChyMan1 from Caldicellulosiruptor
hydrothermalis comprising the amino acid sequence of SEQ ID NO: 4,
or another GH5 TceMan1 polypeptide from Thermobifida
cellulosilytica, comprising the amino acid sequence of SEQ ID NO:5.
The performance of hydrolyzing a given biomass substrate can be
measured using the amount of total soluble sugars produced from a
given lignocellulosic biomass under a given set of saccharification
conditions. The performance of hydrolyzing a given biomass
substrate can also be measured using the amount of glucose produced
from a given lignocellulosic biomass substrate under a
saccharification condition or the % glucan conversion from that
biomass substrate. For example, % glucan conversion can be assessed
using a method described in Example 9 (herein). As such, a MauMan1
polypeptide of the compositions and methods herein, when included
in a given enzyme composition in a certain amount, confers at least
a 5% increase (for example, a 5% increase, a 7% increase, a 10%
increase, a 11% increase, a 12% increase, a 13% increase, a 14%
increase, a 15% increase, or a higher percent increase) in % glucan
conversion when it is a part of an enzyme composition as compared
to the otherwise same enzyme composition comprising the same amount
of ChyMan1, or the same amount of TceMan1, under the same
hydrolysis conditions. Alternatively or in addition, the
performance of hydrolyzing a given biomass substrate can be
measured using the amount of xylose produced from a given
lignocellulosic biomass substrate under a saccharification
condition or the % xylan conversion from that substrate. For
example % xylan conversion can be assessed using a method described
in Example 9 (herein). As such, a MauMan1 polypeptide of the
compositions and methods herein, when included in a given enzyme
composition in a certain amount, confers at least a 5% increase
(for example, a 5% increase, a 7% increase, a 10% increase, a 11%
increase, a 12% increase, a 13% increase, a 14% increase, a 15%
increase, or a higher percent increase) in % xylan conversion when
it is a part of an enzyme composition as compared to the otherwise
same enzyme composition comprising the same amount of ChyMan1, or
the same amount of TceMan1, under the same hydrolysis
conditions.
[0028] Furthermore, the performance of hydrolyzing a given biomass
substrate can be measured by the extent or degree of liquefaction
or viscosity reduction of the biomass substrate or the speed of
such liquefaction or viscosity reduction of a given substrate
having a particular solids level. The viscosity reduction and/or
liquefaction and the rate thereof can be assessed using a method
described in Example 10 (herein). As such a MauMan1 polypeptide of
the compositions and methods herein, when included in a given
enzyme composition in a certain amount, confers at least a 5%
higher viscosity reduction or level of liquefaction as compared to
an otherwise same enzyme composition comprising the same amount of
ChyMan1 or the same amount of TceMan1, under the same hydrolysis
conditions and after the hydrolysis reaction is carried on for the
same time period.
[0029] Aspects of the present compositions and methods include a
recombinant polypeptide comprising an amino acid sequence that is
at least 55% identical to the amino acid sequence of SEQ ID NO: 2,
wherein the polypeptide has beta-mannanase activity. In some
aspects, a MauMan1 polypeptide and/or as it is applied in an enzyme
composition or in a method to hydrolyze a lignocellulosic biomass
substrate is (a) derived from, obtainable from, or produced by
Mahella australiensis, for example, an endophytic bacteria Mahella
sp.; (b) a recombinant polypeptide comprising an amino acid
sequence that is at least 55% (e.g., at least 55%, 60%, 65%, 70%,
75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or
100%) identical to the amino acid sequence of SEQ ID NO:2; (c) a
recombinant polypeptide comprising an amino acid sequence that is
at least 55% (e.g., at least 55%, 60%, 65%, 70%, 75%, 80%, 85%,
90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%)
identical to the catalytic domain of SEQ ID NO:2, namely amino acid
residues 28 to 512; (d) a recombinant polypeptide comprising an
amino acid sequence that is at least 55% (e.g., at least 55%, 60%,
65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,
98%, 99%, or 100%) identical to the mature form of amino acid
sequence of SEQ ID NO:3, namely amino acid residues 28 to 512 of
SEQ ID NO:2; or (e) a fragment of (a), (b), (c) or (d) having
beta-mannanase activity. In certain embodiments, it is provided a
variant polypeptide having beta-mannanase activity, which comprises
a substitution, a deletion and/or an insertion of one or more amino
acid residues of SEQ ID NO:2 or SEQ ID NO:3. In certain
embodiments, the polypeptide comprises an amino acid sequence that
is at least 80% identical to the amino acid sequence of SEQ ID NO:2
or SEQ ID NO: 3. In certain embodiments, the polypeptide comprises
an amino acid sequence that is at least 90% identical to the amino
acid sequence of SEQ ID NO:2 or SEQ ID NO: 3. In certain
embodiments, the polypeptide comprises an amino acid sequence that
is at least 95% identical to the amino acid sequence of SEQ ID NO:2
or SEQ ID NO: 3. In certain embodiments, the polypeptide comprises
an amino acid sequence that is at least 99% identical to the amino
acid sequence of SEQ ID NO:2 or SEQ ID NO: 3.
[0030] In certain embodiments, the MauMan1 polypeptide has a pH
optimum of about pH 6.0. The MauMan1 polypeptide retains greater
than 70% of its maximum activity between pH 4.0 and pH 9.0.
[0031] In certain embodiments, the MauMan1 polypeptide has an
optimum temperature of about 80.degree. C. The MauMan1 polypeptide
retains greater than 70% of its maximum activity between the
temperatures of about 70.degree. C. and about 92.degree. C.
[0032] In certain embodiments, the MauMan1 polypeptide has good
thermostability. For example, the MauMan1 polypeptide retains about
50% of the beta-mannanase activity when incubated for about 2 hours
at a temperature of about 72.degree. C. In certain embodiments, the
polypeptides retains at least 99% of the beta-mannanase activity
when incubated for about 2 hours at a temperature of lower than
about 55.degree. C.
[0033] Aspects of the present compositions and methods include a
composition comprising the recombinant MauMan1 polypeptide as
described herein and one or more cellulases. In some embodiments,
the one or more cellulases may be selected from one or more
endoglucanases, one or more cellobiohydrolases and/or one or more
beta-glucosidases.
[0034] Aspects of the present compositions and methods include a
composition comprising the recombinant MauMan1 polypeptide as
described herein and one or more hemicellulases. In some
embodiments, the one or more other hemicellulases may be selected
from one or more xylanases, beta-xylosidases,
alpha-L-arabinofuranosidases and one or more other mannanases.
[0035] Aspects of the present compositions and methods include a
composition comprising the recombinant MauMan1 polypeptide as
described herein and one or more cellulases and one or more other
hemicellulases. For example, the one or more cellulases may be
selected from endoglucanases, cellobiohydrolases, and/or
beta-glucosidases, and the one or more other hemicellulases may
include xylanases, beta-xylosidases, alpha-L-arabinofuranosidases
and other mannanases.
[0036] As demonstrated herein, the MauMan1 polypeptides described
herein can impart, to an enzyme mixture or composition comprising a
MauMan1 polypeptide in addition to one or more cellulases, an
improved capacity to hydrolyze, saccharify, or degrade a given
lignocellulosic biomass substrate, which has optionally been
subject to pretreatment, and further optionally having had at least
some of its xylan-containing components removed or separated from
the glucan-containing components. Such improved capacity to
hydrolyze, saccharify, or degrade a given lignocellulosic biomass
substrate may be evidenced by a measurably higher % glucan
conversion achieved using a given enzyme composition comprising at
least one cellulase, and a MauMan1 polypeptide in an amount of as
high as about 20 wt. % (for example, up to about 2 wt. %, up to
about 5 wt. %, up to about 7 wt. %, up to about 10 wt. %, up to
about 12 wt. %, up to about 15 wt. %, up to about 16 wt. %, up to
about 17 wt. %, up to about 18 wt. %, up to about 19 wt. %, up to
about 20 wt. %) of the enzyme composition, to hydrolyze a
particular lignocellulosic biomass substrate, as compared to a
counterpart enzyme composition comprising all the same other
enzymes in the same proportion but comprising no MauMan1
polypeptide.
[0037] The MauMan1 polypeptides described herein can alternatively
or additionally impart, to an enzyme mixture or composition
comprising a MauMan1 polypeptide in addition to one or more other
hemicellulases, an improved capacity to hydrolyze, saccharify, or
degrade a given xylan-containing lignocellulosic biomass substrate,
which has optionally been subject to pretreatment, and further
optionally having at least had some of its xylan-containing
components removed or separated from its glucan-containing
components. Such improved capacity to hydrolyze, saccharify, or
degrade a given lignocellulosic biomass substrate may be evidenced
by a measurably higher % xylan conversion achieved using a given
enzyme composition comprising at least one other hemicellulase, and
a MauMan1 polypeptide in an amount of as high as about 20 wt. %
(for example, up to about 2 wt. %, up to about 5 wt. %, up to about
7 wt. %, up to about 10 wt. %, up to about 12 wt. %, up to about 15
wt. %, up to about 16 wt. %, up to about 17 wt. %, up to about 18
wt. %, up to about 19 wt. %, up to about 20 wt. %) of the enzyme
composition to hydrolyze a xylan-containing lignocellulosic biomass
substrate or a xylan-containing component derived therefrom, as
compared a counterpart enzyme composition comprising all the same
other enzymes in the same proportion but comprising no MauMan1
polypeptide.
[0038] Aspects of the present compositions and methods include a
composition comprising a recombinant MauMan1 polypeptide as
detailed herein and a lignocellulosic biomass. Suitable
lignocellulosic biomass may be, for example, derived from an
agricultural crop, a byproduct of a food or feed production, a
lignocellulosic waste product, a plant residue, including, for
example, a grass residue, or a waste paper or waste paper product.
Certain particularly suitable biomass may be one that comprises at
least a measurable level of galactoglucomannan (GGM) and/or
glucomannan (GM). Suitably the biomass may preferably be one that
is rich in galactoglucomannan (GGM) and/or in glucomannan (GM), for
example one that comprises at least about 0.5 wt. % (e.g., 0.5 wt.
%, at least about 0.7 wt. %, at least about 1.0 wt. %, at least
about 1.2 wt. %, at least about 1.5 wt. %, at least about 2.0 wt.
%, at least about 2.5 wt. %, or more) GGM, or at least about 0.5
wt. % (e.g., 0.5 wt. %, at least about 0.7 wt. %, at least about
1.0 wt. %, at least about 1.2 wt. %, at least about 1.5 wt. %, at
least about 2.0 wt. %, at least about 2.5 wt. %, or more) GM, or at
least about 0.5 wt. % (e.g., 0.5 wt. %, at least about 0.7 wt. %,
at least about 1.0 wt. %, at least about 1.2 wt. %, at least about
1.5 wt. %, at least about 2.0 wt. %, at least about 2.5 wt. %, at
least about 3.0 wt. %, at least about 3.5 wt. %, at least about 4.0
wt. %, at least about 4.5 wt. %, at least about 5.0 wt. %, or more)
of GGM and GM combined. In certain embodiments, the lignocellulosic
biomass has been subject to one or more pretreatment steps in order
to render xylan, hemicelluloses, cellulose and/or lignin material
more accessible or susceptible to enzymes and thus more amendable
to enzymatic hydrolysis. A suitable pretreatment method may be, for
example, subjecting biomass material to a catalyst comprising a
dilute solution of a strong acid and a metal salt in a reactor.
See, e.g., U.S. Pat. Nos. 6,660,506, 6,423,145. Alternatively, a
suitable pretreatment may be, for example, a multi-stepped process
as described in U.S. Pat. No. 5,536,325. In certain embodiments,
the biomass material may be subject to one or more stages of dilute
acid hydrolysis using about 0.4% to about 2% of a strong acid, in
accordance with the disclosures of U.S. Pat. No. 6,409,841. Further
embodiments of pretreatment methods may include those described in,
for example, U.S. Pat. No. 5,705,369; in Gould, (1984) Biotech.
& Bioengr., 26:46-52; in Teixeira et al., (1999) Appl. Biochem
& Biotech., 77-79:19-34; in International Published Patent
Application WO2004/081185; or in U.S. Patent Publication No.
20070031918, or International Published Patent Application
WO06110901. A non-limiting example of a suitable lignocellulosic
biomass substrate is a softwood substrated pretreated using the US
Department of Agriculture's SPORL protocol, as described in Example
10 herein. Another non-limiting example of a suitable
lignocellulosic biomass substrate is an akaline KRAFT-pretreated
softwood pulp FPP-27.
[0039] The present invention also pertains to isolated
polynucleotides encoding polypeptides having beta-mannanase
activity, wherein the isolated polynucleotides are selected
from:
(1) a polynucleotide encoding a polypeptide comprising an amino
acid sequence having at least 55% (e.g., at least 55%, 60%, 65%,
70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%,
99%, or 100%) identity to SEQ ID NO:2 or to SEQ ID NO:3; (2) a
polynucleotide having at least 55% (e.g., at least 55%, 60%, 65%,
70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%,
99%, or 100%) identity to SEQ ID NO:1, or hybridizes under medium
stringency conditions, high stringency conditions, or very high
stringency conditions to SEQ ID NO:1, or to a complementary
sequence thereof.
[0040] Aspects of the present compositions and methods include
methods of making or producing a MauMan1 polypeptide having
beta-mannanase activity, employing an isolated nucleic acid
sequence encoding the recombinant polypeptide comprising an amino
acid sequence that is at least 55% identical (e.g., at least 55%,
60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%,
97%, 98%, 99%, or 100%) to that of SEQ ID NO:2, or that of the
mature sequence SEQ ID NO:3. In some embodiments, the polypeptide
further comprises a native or non-native signal peptide such that
the MauMan1 polypeptide that is produced is secreted by a host
organism, for example, the signal peptide comprises a sequence that
is at least 90% identical to any one of SEQ ID NOs:9-37 to allow
for heterologous expression in a variety of fungal host cells,
yeast host cells and bacterial host cells. In certain embodiments
the isolated nucleic acid comprises a sequence that is at least 55%
(e.g., at least 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%,
93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID
NO:1. In certain embodiments, the isolated nucleic acid further
comprises a nucleic acid sequence encoding a signal peptide
sequence. In certain embodiments, the signal peptide sequence may
be one selected from SEQ ID NOs:9-37. In certain particular
embodiments, a nucleic acid sequence encoding the signal peptide
sequence of SEQ ID NO:13 or 14 is used to express a MauMan1
polypeptide in Trichoderma reesei.
[0041] Aspects of the present compositions and methods include an
expression vector comprising the isolated nucleic acid as described
above in operable combination with a regulatory sequence.
[0042] Aspects of the present compositions and methods include a
host cell comprising the expression vector. In certain embodiments,
the host cell is a bacterial cell or a fungal cell.
[0043] Aspects of the present compositions and methods include a
composition comprising the host cell described above and a culture
medium. Aspects of the present compositions and methods include a
method of producing a MauMan1 polypeptide comprising: culturing the
host cell described above in a culture medium, under suitable
conditions to produce the beta-mannanase.
[0044] Aspects of the present compositions and methods include a
composition comprising a MauMan1 polypeptide in the supernatant of
a culture medium produced in accordance with the methods for
producing the beta-mannanase as described above.
[0045] In some aspects the present invention is related to nucleic
acid constructs, recombinant expression vectors, engineered host
cells comprising a polynucleotide encoding a polypeptide having
beta-mannanase activity, as described above and herein. In further
aspects, the present invention pertains to methods of preparing or
producing the beta-mannanase polypeptides of the invention or
compositions comprising such beta-mannanase polypeptides using the
nucleic acid constructs, recombinant expression vectors, and/or
engineered host cells. In particular, the present invention is
related, for example, to a nucleic acid constructs comprising a
suitable signal peptide operably linked to the mature sequence of
the beta-mannanase that is at least 55% identical to SEQ ID NO:2 or
to the mature sequence of SEQ ID NO:3, or is encoded by a
polynucleotide that is at least 55% identical to SEQ ID NO:1, an
isolated polynucleotide, a nucleic acid construct, a recombinant
expression vector, or an engineered host cell comprising such a
nucleic acid construct. In some embodiments, the signal peptide and
beta-mannanase sequences are derived from different
microorganisms.
[0046] Also provided is an expression vector comprising the
isolated nucleic acid in operable combination with a regulatory
sequence. Additionally, a host cell is provided comprising the
expression vector. In still further embodiments, a composition is
provided, which comprises the host cell and a culture medium.
[0047] In some embodiments, the host cell is a bacterial cell or a
fungal cell.
[0048] In further embodiments, the MauMan1 polypeptide is
heterologously expressed by a host cell. For example, the MauMan1
polypeptide is expressed by an engineered microorganism that is not
Mahella australiensis. In some embodiments, the MauMan1 polypeptide
is co-expressed with one or more cellulase genes. In some
embodiments, the MauMan1 polypeptide is co-expressed with one or
more other hemicellulase genes.
[0049] In some aspects, compositions comprising the recombinant
MauMan1 polypeptides of the preceding paragraphs and methods of
preparing such compositions are provided. In some embodiments, the
composition further comprises one or more cellulases, whereby the
one or more cellulases are co-expressed by a host cell with the
MauMan1 polypeptide. In other embodiments, compositions comprising
the MauMan1 polypeptides may be an admixture of an isolated MauMan1
polypeptide, optionally purified, physically blended with one or
more cellulases and/or other enzymes. For example, the one or more
cellulases can be selected from no or one or more
beta-glucosidases, one or more cellobiohydrolyases, and/or one or
more endoglucanases. In certain specific embodiments, such
beta-glucosidases, cellobiohydrolases and/or endoglucanases, if
present, can be co-expressed with the MauMan1 polypeptide by a
single host cell. In some embodiments, at least two of the two or
more cellulases may be heterologous to each other or derived from
different organisms. For example, the composition may comprise at
least one beta-glucosidase and at least one cellobiohydrolase,
whereby that beta-glucosidase and that cellobiohydrolase are not
from the same microorganism. In some embodiments, one or more of
the cellulases are endogenous to the host cell, but are
overexpressed or expressed at a level that is different from that
would otherwise be naturally-occurring in the host cell. For
example, one or more of the cellulases may be a Trichoderma reesei
CBH1 and/or CBH2, which are native to a Trichoderma reesei host
cell, but either or both CBH1 and CBH2 are overexpressed or
underexpressed when they are co-expressed in the Trichoderma reesei
host cell with a MauMan1 polypeptide.
[0050] In certain embodiments, the composition comprising the
recombinant MauMan1 polypeptide may further comprise one or more
other hemicellulases, whereby the one or more other hemicellulases
are co-expressed by a host cell with the MauMan1 polypeptide. For
example, the one or more other hemicellulases can be selected from
one or more other beta-mannanases, one or more xylanases, one or
more beta-xylosidases, and/or one or more L-arabinofuranosidases.
In certain embodiments, such other mannanases, xylanases,
beta-xylosidases and L-arabinofuranosidases, if present, can be
co-expressed with the MauMan1 polypeptide by a single host cell; or
alternatively, one or more or all of such other mannanases,
xylanases, beta-xylosidases and L-arabinofuranosidases, if present,
are not co-expressed with the MauMan1 polypeptides in a single host
cell, but are rather physically mixed or blended together to form
an enzyme composition after the individual enzymes are produced by
their respective host cells.
[0051] In further aspects, the composition comprising the
recombinant MauMan1 polypeptide may further comprise one or more
celluases and one or more other hemicelluases, whereby the one or
more cellulases and/or one or more other hemicellulases are
co-expressed by a host cell with the MauMan1 polypeptide. For
example, a MauMan1 polypeptide may be co-expressed with one or more
beta-glucosidases, one or more cellobiohydrolases, one or more
endoglucanases, one or more endo-xylanases, one or more
beta-xylosidases, and/or one or more L-arabinofuranosidases, in
addition to other non-cellulase non-hemicellulase enzymes or
proteins in the same host cell. Alternatively, the composition
comprising the recombinant MauMan1 polypeptide comprising one or
more cellulases and one or more other hemicellulases may be
prepared by physically mixing the MauMan1 polypeptide with one or
more cellulases and one or more other hemicellulases post
production, whereby the MauMan1 polypeptide and the one or more
cellulases and one or more other hemicellulases are produced from
different host cells. Aspects of the present compositions and
methods thus include a composition comprising the host cell
described above co-expressing a number of enzymes in addition to
the MauMan1 polypeptide and a culture medium. Alternatively,
aspects of the present compositions and methods include a first
composition comprising a first host cell expressing a MauMan1,
optionally in addition to one or more other enzymes/proteins, and a
second composition comprising a second host cell expressing, for
example, one or more cellulases and/or one or more other
hemicellulases, and optionally a third composition comprising a
third host cell expressing, for example, one or more other
cellulases and/or one or more other hemicellulases that are
different from those that are expressed by the first and second
host cells. Such first, second, and third compositions resulting
from enzyme production from the host cells, if appropriate, can
suitably be physically blended or mixed to form an admixture of
enzymes that form the present composition. Also provided are
compositions that comprise the MauMan1 polypeptide and the other
enzymes produced in accordance with the methods herein in
supernatant of a culture medium or culture media, as appropriate.
Such supernatant of the culture medium can be used as is, with
minimum or no post-production processing, which may typically
include filtration to remove cell debris, cell-kill procedures,
and/or ultrafiltration or other steps to enrich or concentrate the
enzymes therein. Such supernatants are called "whole broths" or
"whole cellulase broths" herein.
[0052] In further aspects, the present invention pertains to a
method of applying or using the composition as described above
under conditions suitable for degrading or converting a cellulosic
material and for producing a substance from a cellulosic
material.
[0053] In a further aspect, methods for degrading or converting a
cellulosic material into fermentable sugars are provided,
comprising: contacting the cellulosic material, preferably having
already been subject to one or more pretreatment steps, with the
MauMan1 polypeptides or the compositions comprising such
polypeptides of one of the preceding paragraphs to yield
fermentable sugars.
[0054] Accordingly the instant specification is drawn to the
following particular aspects:
[0055] In a first aspect, a recombinant polypeptide comprising an
amino acid sequence that is at least 55% identical to the amino
acid sequence of SEQ ID NO:2 or SEQ ID NO:3, wherein the
polypeptide has beta-mannanase activity.
[0056] In a second aspect, the recombinant polypeptide of the first
aspect, wherein the polypeptide improves the hydrolysis performance
of a cellulase composition when the polypeptide constitutes up to
20 wt. % of the cellulase composition, wherein the improved
hydrolysis performance comprises:
[0057] (a) an increased % glucan conversion, an increased % xylan
conversion, and/or an increased % glucan and % xylan conversion
from a given lignocellulosic biomass substrate under the same
hydrolysis conditions; or
[0058] (b) an at least about 5% faster viscosity reduction of a
given lignocellulosic biomass substrate under the same hydrolysis
conditions.
[0059] In a third aspect, the recombinant polypeptide of the first
or the second aspect, wherein the polypeptide has an increased
beta-mannanase activity as compared to the beta-mannanase activity
of ChyMan1 comprising SEQ ID NO:4.
[0060] In a fourth aspect, the recombinant polypeptide of the first
or the second aspect, wherein the polypeptide has an increased
beta-mannanase activity as compared to the beta-mannanase activity
of TceMan1 comprising SEQ ID NO:5.
[0061] In a fifth aspect, the recombinant polypeptide of any one of
the first to the fourth aspects, wherein the polypeptide retains
greater than 70% of the beta-mannanase activity when incubated at a
pH range from pH 4.0 to pH 9.0.
[0062] In a sixth aspect, the recombinant polypeptide of any one of
the first to fifth aspects, wherein the polypeptide has optimum
beta-mannanase activity at a pH of about 6.0.
[0063] In a seventh aspect, the recombinant polypeptide of any one
of the first to sixth aspects, wherein the polypeptide retains at
least 70% or more of the beta-mannanase activity when incubated at
a temperature of between 70.degree. C. and 92.degree. C.
[0064] In an eighth aspect, the recombinant polypeptide of any one
of the first to seventh aspects, wherein the polypeptide has
optimum beta-mannanase activity at a temperature of about
80.degree. C. or above.
[0065] In a ninth aspect, the recombinant polypeptide of any one of
the first to eighth aspects, wherein the polypeptide retains at
least 50% of the beta-mannanase activity when incubated for about 2
hours at a temperature of about 72.degree. C.
[0066] In a tenth aspect, the recombinant polypeptide of any one of
the first to ninth aspects, wherein the polypeptide retains at
least 99% of the beta-mannanase activity when incubated for about 2
hours at a temperature of up to 55.degree. C.
[0067] In an 11.sup.th aspect, the recombinant polypeptide of any
one of the first to tenth aspects, wherein the polypeptide
comprises an amino acid sequence that is at least 60% identical to
the amino acid sequence of SEQ ID NO:2 or SEQ ID NO:3.
[0068] In a 12.sup.th aspect, the recombinant polypeptide of any
one of the first to 11.sup.th aspects, wherein the polypeptide
comprises an amino acid sequence that is at least 65% identical to
the amino acid sequence of SEQ ID NO:2 or SEQ ID NO:3.
[0069] In a 13.sup.th aspect, the recombinant polypeptide of any
one of the first to 12.sup.th aspects, wherein the polypeptide
comprises an amino acid sequence that is at least 70% identical to
the amino acid sequence of SEQ ID NO:2 or SEQ ID NO:3.
[0070] In a 14.sup.th aspect, an enzyme composition comprising the
recombinant polypeptide of any one of the first to 13.sup.th
aspects, further comprising one or more cellulases.
[0071] In a 15.sup.th aspect, the enzyme composition of the
14.sup.th aspect, wherein the one or more cellulases are selected
from one or more beta-glucosidases, one or more cellobiohydrolases,
and one or more endoglucanases.
[0072] In a 16.sup.th aspect, an enzyme composition comprising the
recombinant polypeptide of any one of the first to 13.sup.th
aspects, further comprising one or more other hemicellulases.
[0073] In a 17.sup.th aspect, the enzyme composition of the
16.sup.th aspect, wherein the one or more other hemicellulases are
selected from one or more other beta-mannanases, one or more one or
more xylanases, one or more beta-xylosidases, and one or more
L-arabinofuranosidases.
[0074] In an 18.sup.th aspect, a nucleic acid encoding the
recombinant polypeptide of any one of the first to 13.sup.th
aspects.
[0075] In a 19.sup.th aspect, the nucleic acid of the 18.sup.th
aspect, wherein the polypeptide further comprises a signal peptide
sequence.
[0076] In a 20.sup.th aspect, the nucleic acid of the 19.sup.th
aspect, wherein the signal peptide sequence is selected from any
one of SEQ ID NOs:9-37.
[0077] In a 21.sup.st aspect, an expression vector comprising the
nucleic acid of any one of the 18.sup.th to 20.sup.th aspects, in
operable combination with a regulatory sequence.
[0078] In a 22.sup.nd aspect, a host cell comprising the expression
vector of the 21.sup.st aspect.
[0079] In a 23.sup.rd aspect, the host cell of the 22.sup.nd
aspect, wherein the host cell is a bacterial cell or a fungal
cell.
[0080] In a 24.sup.th aspect, a composition comprising the host
cell of the 22.sup.nd or 23.sup.rd aspect and a culture medium.
[0081] In a 25.sup.th aspect, a method of producing a
beta-mannanase, comprising: culturing the host cell of the
22.sup.nd or 23.sup.rd aspect, in a culture medium, under suitable
conditions to produce the beta-mannanase.
[0082] In a 26.sup.th aspect, a composition comprising the
beta-mannanase produced in accordance with the method of the
25.sup.th aspect in supernatant of the culture medium.
[0083] In a 27.sup.th aspect, a method for hydrolyzing a
lignocellulosic biomass substrate, comprising: contacting the
lignocellulosic biomass substrate with the polypeptide of any one
of the first to 13.sup.th aspects, or the composition of any one of
the 14.sup.th to 17.sup.th and 26.sup.th aspects, to yield glucose
and other sugars.
[0084] In a 28.sup.th aspect, the method of the 27.sup.th aspect,
wherein the lignocellulosic biomass substrate comprises up to about
20 wt. %, up to about 15%, or up to about 10 wt. % of
galactoglucomannan and/or glucomannan.
[0085] In a 29.sup.th aspect, a composition comprising the
recombinant polypeptide of any one of the first to 13.sup.th
aspects, and a lignocellulosic biomass substrate.
[0086] In a 30.sup.th aspect, the composition of the 29.sup.th
aspect, wherein the lignocellulosic biomass substrate comprises up
to about 20 wt. %, or up to about 15 wt. %, or up to about 10 wt. %
of galactoglucomannan and/or glucomannan.
BRIEF DESCRIPTION OF THE DRAWINGS
[0087] FIG. 1 depicts a map of the p2JM103BBI vector.
[0088] FIG. 2 depicts a map of the p2JM(aprE-MauMan1)
construct.
[0089] FIG. 3 depicts a pH profile of MauMan1. The effect of pH on
beta-mannanase activity of MauMan1 was measured at 50.degree. C.
for 10 minutes using 1% locust bean gum as 2 to 9 at 50.degree. C.
for 10 min with locust bean gum as the substrate 2 to 9 at
50.degree. C. for 10 min with locust bean gum as the substrate
substrate in 50 mM sodium citrate and 50 mM sodium phosphate buffer
adjusted to individual pH values ranging between pH 2-9. The
mannanase activity of the MauMan1 polypeptide at its pH optimum was
normalized to 100%, and the mannanase activity of the same
polypeptide at other pH values were depicted as relative activity
to that at the pH optimum.
[0090] FIG. 4 depicts a temperature profile of MauMan1. The effect
of temperature change on beta-mannanase activity of MauMan1 was
measured at individual temperature values ranging between
40.degree. C. and 90.degree. C. for 10 minutes using 1% locust bean
gum as substrate in a 50 mM sodium citrate buffer, at pH 6.0. The
mannanase activity of the MauMan1 polypeptide at its temperature
optimum was normalized to 100%, and the mannanase activity of the
same polypeptide at other temperature values were depicted as
relative activity to that at the temperature optimum.
[0091] FIG. 5 depicts a thermostability profile of MauMan1. The
thermostability of MauMan1 was determined by incubation in 50 mM
sodium citrate buffer at pH 6.0 at a set temperature within the
range of 40.degree. C. and 90.degree. C. for 2 hours. After
incubation, the remaining mannanase activity at each of the
incubation temperature was measured. The activity measured from a
control sample of the MauMan1 polypeptide kept on ice for the same
2 hours was used as the 100% activity to normalize the residual
activity measurements.
[0092] FIGS. 6A-6D depict the comparison of levels of hydrolysis
and viscosity reduction achieved by a commercial
cellulase/hemicellulase composition Accellerase.RTM. TRIO.TM. vs. a
blend of 9 parts Accellerase.RTM. TRIO.TM. with 1 part (i.e., 10
wt. %) of a MauMan1 polypeptide, as compared to the same blend of
Accellerase.RTM. TRIO.TM. with each of two other beta-mannanases of
GH5, a Caldicellulosiruptor hydrothermalis beta-mannanase of SEQ ID
NO:4 ("ChyMan1") and a Thermobifida cellulosilytica beta-mannanase
of SEQ ID NO:5 ("TceMan1"), of a given biomass substrate, namely
the alkaline KRAFT-pretreated softwood substrate FPP-27, under the
same hydrolysis conditions and at different durations of reaction.
FIG. 6A depicts the results of hydrolysis after 24 hours. FIG. 6B
depicts the results of hydrolysis after 48 hours. FIG. 6C depicts
the results of hydrolysis after 72 hours. FIG. 6D depicts a
timecourse of hydrolysis by MauMan1, ChyMan1, TceMan1, in
conjunction with a given blend of Accellerase.RTM. TRIO.TM. on the
same substrate. Details of the experiments are found in Example
9.
[0093] FIG. 7 depicts the comparison of total hydrolysis of the
FPP-27 alkaline KRAFT-pretreated softwood substrate by
Accellerase.RTM. TRIO.TM. vs. a blend of 9 parts Accellerase.RTM.
TRIO.TM. with 1 part (i.e., 10 wt. %) of a MauMan1 polypeptide, a
Caldicellulosiruptor hydrothermalis beta-mannanase of SEQ ID NO:4
("ChyMan1"), or a Thermobifida cellulosilytica beta-mannanase of
SEQ ID NO:5 ("TceMan1"), following a time course of 24 hours to 168
hours. Details of the experiments are found in Example 9.
[0094] FIG. 8 describes sequences referenced elsewhere herein.
DETAILED DESCRIPTION
Overview
[0095] Described herein are compositions and methods relating to a
recombinant beta-mannanase belonging to glycosyl hydrolase family 5
from Mahella australiensis. The present compositions and methods
are based, in part, on the observations that recombinant MauMan1
polypeptides confer to a cellulase and/or hemicellulase composition
comprising at least one cellulase and/or at least one other
hemicellulase, an improved capacity to hydrolyze a lignocellulosic
biomass material or feedstock than other known beta-mannanases of
similar pH optimums and/or temperature optimums. The present
compositions and methods are also based on the observation that
recombinant MauMan1 polypeptides confers rapid viscosity reduction
when compositions comprising the polypeptides are used to hydrolyze
suitable lignocellulosic biomass substrates, especially when such
substrates are treated at high solids levels, and when such
substrates contain measurable level of galactoglucomannan (GGM)
and/or glucomannan (GM). These features of MauMan1 polypeptides
make them, or variants thereof, suitable for use in numerous
processes, including, for example, in the conversion or hydrolysis
of a lignocellulosic biomass feedstock.
[0096] Before the present compositions and methods are described in
greater detail, it is to be understood that the present
compositions and methods are not limited to particular embodiments
described, as such may, of course, vary. It is also to be
understood that the terminology used herein is for the purpose of
describing particular embodiments only, and is not intended to be
limiting, since the scope of the present compositions and methods
will be limited only by the appended claims.
[0097] Where a range of values is provided, it is understood that
each intervening value, to the tenth of the unit of the lower limit
unless the context clearly dictates otherwise, between the upper
and lower limit of that range and any other stated or intervening
value in that stated range, is encompassed within the present
compositions and methods. The upper and lower limits of these
smaller ranges may independently be included in the smaller ranges
and are also encompassed within the present compositions and
methods, subject to any specifically excluded limit in the stated
range. Where the stated range includes one or both of the limits,
ranges excluding either or both of those included limits are also
included in the present compositions and methods.
[0098] Certain ranges are presented herein with numerical values
being preceded by the term "about." The term "about" is used herein
to provide literal support for the exact number that it precedes,
as well as a number that is near to or approximately the number
that the term precedes. In determining whether a number is near to
or approximately a specifically recited number, the near or
approximating unrecited number may be a number which, in the
context in which it is presented, provides the substantial
equivalent of the specifically recited number. For example, in
connection with a numerical value, the term "about" refers to a
range of -10% to +10% of the numerical value, unless the term is
otherwise specifically defined in context. In another example, the
phrase a "pH value of about 6" refers to pH values of from 5.4 to
6.6, unless the pH value is specifically defined otherwise.
[0099] The headings provided herein are not limitations of the
various aspects or embodiments of the present compositions and
methods which can be had by reference to the specification as a
whole. Accordingly, the terms defined immediately below are more
fully defined by reference to the specification as a whole.
[0100] The present document is organized into a number of sections
for ease of reading; however, the reader will appreciate that
statements made in one section may apply to other sections. In this
manner, the headings used for different sections of the disclosure
should not be construed as limiting.
[0101] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which the present compositions and
methods belongs. Although any methods and materials similar or
equivalent to those described herein can also be used in the
practice or testing of the present compositions and methods,
representative illustrative methods and materials are now
described.
[0102] All publications and patents cited in this specification are
herein incorporated by reference as if each individual publication
or patent were specifically and individually indicated to be
incorporated by reference and are incorporated herein by reference
to disclose and describe the methods and/or materials in connection
with which the publications are cited. The citation of any
publication is for its disclosure prior to the filing date and
should not be construed as an admission that the present
compositions and methods are not entitled to antedate such
publication by virtue of prior invention. Further, the dates of
publication provided may be different from the actual publication
dates which may need to be independently confirmed.
[0103] In accordance with this detailed description, the following
abbreviations and definitions apply. Note that the singular forms
"a," "an," and "the" include plural referents unless the context
clearly dictates otherwise. Thus, for example, reference to "an
enzyme" includes a plurality of such enzymes, and reference to "the
dosage" includes reference to one or more dosages and equivalents
thereof known to those skilled in the art, and so forth.
[0104] It is further noted that the claims may be drafted to
exclude any optional element. As such, this statement is intended
to serve as antecedent basis for use of such exclusive terminology
as "solely," "only" and the like in connection with the recitation
of claim elements, or use of a "negative" limitation.
[0105] The term "recombinant," when used in reference to a subject
cell, nucleic acid, polypeptides/enzymes or vector, indicates that
the subject has been modified from its native state. Thus, for
example, recombinant cells express genes that are not found within
the native (non-recombinant) form of the cell, or express native
genes at different levels or under different conditions than found
in nature. Recombinant nucleic acids may differ from a native
sequence by one or more nucleotides and/or are operably linked to
heterologous sequences, e.g., a heterologous promoter, signal
sequences that allow secretion, etc., in an expression vector.
Recombinant polypeptides/enzymes may differ from a native sequence
by one or more amino acids and/or are fused with heterologous
sequences. A vector comprising a nucleic acid encoding a
beta-mannanase is, for example, a recombinant vector.
[0106] It is further noted that the term "consisting essentially
of," as used herein refers to a composition wherein the
component(s) after the term is in the presence of other known
component(s) in a total amount that is less than 30% by weight of
the total composition and do not contribute to or interferes with
the actions or activities of the component(s).
[0107] It is further noted that the term "comprising," as used
herein, means including, but not limited to, the component(s) after
the term "comprising." The component(s) after the term "comprising"
are required or mandatory, but the composition comprising the
component(s) may further include other non-mandatory or optional
component(s).
[0108] It is also noted that the term "consisting of," as used
herein, means including, and limited to, the component(s) after the
term "consisting of" The component(s) after the term "consisting
of" are therefore required or mandatory, and no other component(s)
are present in the composition.
[0109] As will be apparent to those of skill in the art upon
reading this disclosure, each of the individual embodiments
described and illustrated herein has discrete components and
features which may be readily separated from or combined with the
features of any of the other several embodiments without departing
from the scope or spirit of the present compositions and methods
described herein. Any recited method can be carried out in the
order of events recited or in any other order which is logically
possible.
[0110] "Beta-mannanase" means a polypeptide or polypeptide domain
of an enzyme that has the ability to catalyze the cleavage or
hydrolysis of (1.fwdarw.4)-beta-D-mannosidic linkages of mannans,
galactomannans, and glucomannans.
[0111] As used herein, "MauMan1" or "a MauMan1 polypeptide" refers
to a beta-mannanase belonging to glycosyl hydrolase family 5 (e.g.,
a recombinant beta-mannanase) derived from Mahella australiensis
(and variants thereof), that confers surprising improvements to a
cellulase and/or hemicellulase composition in the composition's
capability to hydrolyze a lignocellulosic biomass substrate,
optionally pretreated, when compared to other known beta-mannanases
of similar pH optimums and/or temperature optimums. The MauMan1
polypeptide can substitute a substantial portion, e.g., up to about
20 wt. % (e.g., up to about 20 wt. %, up to about 15 wt. %, up to
about 10 wt. %, up to about 9 wt. %, up to about 8 wt. %, up to
about 7 wt. %, up to about 6 wt. %, up to about 5 wt. %, up to
about 4 wt. %, up to about 3 wt. %, up to about 2 wt. %, up to
about 1 wt. %) of a cellulase and/or hemicellulase mixture and
achieve equal or better hydrolysis of a given lignocellulosic
biomass substrate under the same conditions. This allows the use of
less cellulases/hemicellulases and more efficient biomass
hydrolysis, thus making the overall cellulosic biomass conversion
process more economically feasible and sustainable. The MauMan1
polypeptide herein was also surprisingly found to confer rapid
viscosity reduction or liquefaction, particularly prominently when
the biomass substrate is treated with enzyme at high solids levels.
According to aspects of the present compositions and methods,
MauMan1 polypeptides include those having the amino acid sequence
depicted in SEQ ID NO:2, as well as derivative or variant
polypeptides having at least 55%, at least 60%, at least 65%, at
least 70%, at least 75%, at least 80%, at least 85%, at least 90%,
at least 91%, at least 92%, at least 93%, at least 94%, at least
95%, at least 96%, at least 97%, at least 98%, or at least 99%
sequence identity to the amino acid sequence of SEQ ID NO:2, or to
the mature sequence SEQ ID NO:2, or to a fragment of at least 80
residues in length of SEQ. ID NO:2, wherein the MauMan1
polypeptides not only have beta-mannanase activity and capable of
catalyzing the conversion hydrolysis of
(1.fwdarw.4)-beta-D-mannosidic linkages of mannans, galactomannans,
and glucomannans, but also have higher beta-mannanase activity than
other beta-mannases of similar pH optimums and/or temperature
optimums, and confer rapid viscosity reduction and liquefaction of
high solids biomass substrates, a property that has not been
observed with other known beta-mannanases.
[0112] "Family 5 glycosyl hydrolase" or "GH5" refers to
polypeptides falling within the definition of glycosyl hydrolase
family 5 according to the classification by Henrissat, Biochem. J.
280:309-316 (1991), and by Henrissat & Cairoch, Biochem. J.,
316:695-696 (1996). Similarly, "Family 26 glycosyl hydrolase" or
"GH26" refers to polypeptides falling within the definition of
glycosyl hydrolase family 26 according to the classification by
Henrissat, Biochem. J. 280:309-316 (1991), and by Henrissat &
Cairoch, Biochem. J., 316:695-696 (1996).
[0113] MauMan1 polypeptides according to the present compositions
and methods described herein can be isolated or purified. By
purification or isolation is meant that the MauMan1 polypeptide is
altered from its natural state by virtue of separating the MauMan1
from some or all of the naturally occurring constituents with which
it is associated in nature. Such isolation or purification may be
accomplished by art-recognized separation techniques such as ion
exchange chromatography, affinity chromatography, hydrophobic
separation, dialysis, protease treatment, ammonium sulphate
precipitation or other protein salt precipitation, centrifugation,
size exclusion chromatography, filtration, microfiltration, gel
electrophoresis or separation on a gradient to remove whole cells,
cell debris, impurities, extraneous proteins, or enzymes undesired
in the final composition. It is further possible to then add
constituents to the MauMan1-containing composition which provide
additional benefits, for example, activating agents,
anti-inhibition agents, desirable ions, compounds to control pH or
other enzymes or chemicals.
[0114] As used herein, "microorganism" refers to a bacterium, a
fungus, a virus, a protozoan, and other microbes or microscopic
organisms.
[0115] As used herein, a "derivative" or "variant" of a polypeptide
means a polypeptide, which is derived from a precursor polypeptide
(e.g., the native polypeptide) by addition of one or more amino
acids to either or both the C- and N-terminal end, substitution of
one or more amino acids at one or a number of different sites in
the amino acid sequence, deletion of one or more amino acids at
either or both ends of the polypeptide or at one or more sites in
the amino acid sequence, or insertion of one or more amino acids at
one or more sites in the amino acid sequence. The preparation of a
MauMan1 derivative or variant may be achieved in any convenient
manner, e.g., by modifying a DNA sequence which encodes the native
polypeptides, transformation of that DNA sequence into a suitable
host, and expression of the modified DNA sequence to form the
derivative/variant MauMan1. Derivatives or variants further include
MauMan1 polypeptides that are chemically modified, e.g.,
glycosylation or otherwise changing a characteristic of the MauMan1
polypeptide. While derivatives and variants of MauMan1 are
encompassed by the present compositions and methods, such derivates
and variants will display improved beta-mannanase activity under
the same lignocellulosic biomass substrate hydrolysis conditions,
when compared to that of a number of other beta-mannanases having
similar pH optimums and/or temperature optimums, for example the
ChyMan1 having the sequence of SEQ ID NO:4, or the TceMan1, having
the sequence of SEQ ID NO:5. In some embodiments, such derivatives
and variants will also confer rapid viscosity reduction and
liquefaction to a cellulase and/or hemicellulase composition,
capable of achieving, for example, at least 10% (e.g., at least
10%, at least 15%, at least 20%, at least 25%, at least 30%, at
least 35%, at least 40%, at least 45%, at least 50%, at least 55%,
at least 60%, at least 65%, at least 70%, at least 75%, at least
80%, at least 90%, at least 95%, at least 100%, or even more)
improved viscosity reduction or higher liquefaction within the same
time period after the biomass substrate is subject to an enzyme
composition comprising a MauMan1 polypeptide herein, as compared to
when that same biomass substrate is subject to a counterpart enzyme
composition having the same amounts, proportion, and types of
enzymes except that the composition does not comprise the MauMan1
polypeptide.
[0116] In certain aspects, a MauMan1 polypeptide of the
compositions and methods herein may also encompasses functional
fragment of a polypeptide or a polypeptide fragment having
beta-mannanase activity, which is derived from a parent
polypeptide, which may be the full length polypeptide comprising or
consisting of SEQ ID NO:2, or the mature sequence comprising or
consisting SEQ ID NO:3. The functional polypeptide may have been
truncated either in the N-terminal region, or the C-terminal
region, or in both regions to generate a fragment of the parent
polypeptide. For the purpose of the present disclosure, a
functional fragment must have at least 20%, more preferably at
least 30%, 40%, 50%, or preferably, at least 60%, 70%, 80%, or even
more preferably at least 90% of the beta-mannanase activity of that
of the parent polypeptide.
[0117] In certain aspects, a MauMan1 derivative/variant will have
anywhere from 55% to 99% (or more) amino acid sequence identity to
the amino acid sequence of SEQ ID NO:2, or to the mature sequence
SEQ ID NO:3, e.g., 55%, 60%, 65%, 70%, 75%, 80%, 85%, 86%, 87%,
88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% amino
acid sequence identity to the amino acid sequence of SEQ. ID NO:2
or to the mature sequence SEQ ID NO:3. In some embodiments, amino
acid substitutions are "conservative amino acid substitutions"
using L-amino acids, wherein one amino acid is replaced by another
biologically similar amino acid. Conservative amino acid
substitutions are those that preserve the general charge,
hydrophobicity/hydrophilicity, and/or steric bulk of the amino acid
being substituted. Examples of conservative substitutions are those
between the following groups: Gly/Ala, Val/Ile/Leu, Lys/Arg,
Asn/Gln, Glu/Asp, Ser/Cys/Thr, and Phe/Trp/Tyr. A derivative may,
for example, differ by as few as 1 to 10 amino acid residues, such
as 6-10, as few as 5, as few as 4, 3, 2, or even 1 amino acid
residue. In some embodiments, a MauMan1 derivative may have an
N-terminal and/or C-terminal deletion, where the MauMan1 derivative
excluding the deleted terminal portion(s) is identical to a
contiguous sub-region in SEQ ID NO: 2 or SEQ ID NO:3.
[0118] As used herein, "percent (%) sequence identity" with respect
to the amino acid or nucleotide sequences identified herein is
defined as the percentage of amino acid residues or nucleotides in
a candidate sequence that are identical with the amino acid
residues or nucleotides in a MauMan1 sequence, after aligning the
sequences and introducing gaps, if necessary, to achieve the
maximum percent sequence identity, and not considering any
conservative substitutions as part of the sequence identity.
[0119] By "homologue" shall mean an entity having a specified
degree of identity with the subject amino acid sequences and the
subject nucleotide sequences. A homologous sequence is taken to
include an amino acid sequence that is at least 50%, 55%, 60%, 65%,
70%, 75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%,
95%, 96%, 97%, 98% or even 99% identical to the subject sequence,
using conventional sequence alignment tools (e.g., Clustal, BLAST,
and the like). Typically, homologues will include the same active
site residues as the subject amino acid sequence, unless otherwise
specified.
[0120] Methods for performing sequence alignment and determining
sequence identity are known to the skilled artisan, may be
performed without undue experimentation, and calculations of
identity values may be obtained with definiteness. See, for
example, Ausubel et al., eds. (1995) Current Protocols in Molecular
Biology, Chapter 19 (Greene Publishing and Wiley-Interscience, New
York); and the ALIGN program (Dayhoff (1978) in Atlas of Protein
Sequence and Structure 5:Suppl. 3 (National Biomedical Research
Foundation, Washington, D.C.). A number of algorithms are available
for aligning sequences and determining sequence identity and
include, for example, the homology alignment algorithm of Needleman
et al. (1970) J. Mol. Biol. 48:443; the local homology algorithm of
Smith et al. (1981) Adv. Appl. Math. 2:482; the search for
similarity method of Pearson et al. (1988) Proc. Natl. Acad. Sci.
85:2444; the Smith-Waterman algorithm (Meth. Mol. Biol. 70:173-187
(1997); and BLASTP, BLASTN, and BLASTX algorithms (see Altschul et
al. (1990) J. Mol. Biol. 2/5:403-410).
[0121] Computerized programs using these algorithms are also
available, and include, but are not limited to: ALIGN or Megalign
(DNASTAR) software, or WU-BLAST-2 (Altschul et al., (1996) Meth.
Enzym., 266:460-480); or GAP, BESTFIT, BLAST, FASTA, and TFASTA,
available in the Genetics Computing Group (GCG) package, Version 8,
Madison, Wis., USA; and CLUSTAL in the PC/Gene program by
Intelligenetics, Mountain View, Calif. Those skilled in the art can
determine appropriate parameters for measuring alignment, including
algorithms needed to achieve maximal alignment over the length of
the sequences being compared. Preferably, the sequence identity is
determined using the default parameters determined by the program.
Specifically, sequence identity can determined by using Clustal W
(Thompson J. D. et al. (1994) Nucleic Acids Res. 22:4673-4680) with
default parameters, i.e.:
[0122] Gap opening penalty: 10.0
[0123] Gap extension penalty: 0.05
[0124] Protein weight matrix: BLOSUM series
[0125] DNA weight matrix: IUB
[0126] Delay divergent sequences %: 40
[0127] Gap separation distance: 8
[0128] DNA transitions weight: 0.50
[0129] List hydrophilic residues: GPSNDQEKR
[0130] Use negative matrix: OFF
[0131] Toggle Residue specific penalties: ON
[0132] Toggle hydrophilic penalties: ON
[0133] Toggle end gap separation penalty OFF
[0134] As used herein, "expression vector" means a DNA construct
including a DNA sequence which is operably linked to a suitable
control sequence capable of affecting the expression of the DNA in
a suitable host. Such control sequences may include a promoter to
affect transcription, an optional operator sequence to control
transcription, a sequence encoding suitable ribosome-binding sites
on the mRNA, and sequences which control termination of
transcription and translation. Different cell types may be used
with different expression vectors. An exemplary promoter for
vectors used in Bacillus subtilis is the AprE promoter; an
exemplary promoter used in Streptomyces lividans is the A4 promoter
(from Aspergillus niger); an exemplary promoter used in E. coli is
the Lac promoter, an exemplary promoter used in Saccharomyces
cerevisiae is PGK1, an exemplary promoter used in Aspergillus niger
is glaA, and an exemplary promoter for Trichoderma reesei is cbhI.
The vector may be a plasmid, a phage particle, or simply a
potential genomic insert. Once transformed into a suitable host,
the vector may replicate and function independently of the host
genome, or may, under suitable conditions, integrate into the
genome itself. In the present specification, plasmid and vector are
sometimes used interchangeably. However, the present compositions
and methods are intended to include other forms of expression
vectors which serve equivalent functions and which are, or become,
known in the art. Thus, a wide variety of host/expression vector
combinations may be employed in expressing the DNA sequences
described herein. Useful expression vectors, for example, may
consist of segments of chromosomal, non-chromosomal and synthetic
DNA sequences such as various known derivatives of SV40 and known
bacterial plasmids, e.g., plasmids from E. coli including col E1,
pCR1, pBR322, pMb9, pUC 19 and their derivatives, wider host range
plasmids, e.g., RP4, phage DNAs e.g., the numerous derivatives of
phage e.g., NM989, and other DNA phages, e.g., M13 and filamentous
single stranded DNA phages, yeast plasmids such as the 2.mu.
plasmid or derivatives thereof, vectors useful in eukaryotic cells,
such as vectors useful in animal cells and vectors derived from
combinations of plasmids and phage DNAs, such as plasmids which
have been modified to employ phage DNA or other expression control
sequences. Expression techniques using the expression vectors of
the present compositions and methods are known in the art and are
described generally in, for example, Sambrook et al., Molecular
Cloning: A Laboratory Manual, Second Edition, Cold Spring Harbor
Press (1989). Often, such expression vectors including the DNA
sequences described herein are transformed into a unicellular host
by direct insertion into the genome of a particular species through
an integration event (see e.g., Bennett & Lasure, More Gene
Manipulations in Fungi, Academic Press, San Diego, pp. 70-76 (1991)
and articles cited therein describing targeted genomic insertion in
fungal hosts).
[0135] As used herein, "host strain" or "host cell" means a
suitable host for an expression vector including DNA according to
the present compositions and methods. Host cells useful in the
present compositions and methods are generally prokaryotic or
eukaryotic hosts, including any transformable microorganism in
which expression can be achieved. Specifically, host strains may be
Bacillus subtilis, Bacillus licheniformis, Streptomyces lividans,
Escherichia coli, Trichoderma reesei, Saccharomyces cerevisiae,
Aspergillus niger, Aspergillus oryzae, Chrysosporium lucknowence,
Myceliophthora thermophila, and various other microbial cells. Host
cells are transformed or transfected with vectors constructed using
recombinant DNA techniques. Such transformed host cells may be
capable of one or both of replicating the vectors encoding MauMan1
(and its derivatives or variants (mutants)) and expressing the
desired peptide product. In certain embodiments according to the
present compositions and methods, "host cell" means both the cells
and protoplasts created from the cells of Trichoderma sp.
[0136] The terms "transformed," "stably transformed," and
"transgenic," used with reference to a cell means that the cell
contains a non-native (e.g., heterologous) nucleic acid sequence
integrated into its genome or carried as an episome that is
maintained through multiple generations.
[0137] The term "introduced" in the context of inserting a nucleic
acid sequence into a cell, means "transfection," "transformation,"
or "transduction," as known in the art.
[0138] A "host strain" or "host cell" is an organism into which an
expression vector, phage, virus, or other DNA construct, including
a polynucleotide encoding a polypeptide of interest (e.g., a
beta-mannanase) has been introduced. Exemplary host strains are
microbial cells (e.g., bacteria, filamentous fungi, and yeast)
capable of expressing the polypeptide of interest. The term "host
cell" includes protoplasts created from cells.
[0139] The term "heterologous" with reference to a polynucleotide
or polypeptide refers to a polynucleotide or polypeptide that does
not naturally occur in a host cell.
[0140] The term "endogenous" with reference to a polynucleotide or
polypeptide refers to a polynucleotide or polypeptide that occurs
naturally in the host cell.
[0141] The term "expression" refers to the process by which a
polypeptide is produced based on a nucleic acid sequence. The
process includes both transcription and translation.
[0142] As used herein, "signal sequence" means a sequence of amino
acids bound to the N-terminal portion of a protein which
facilitates the secretion of the mature form of the protein outside
of the cell. This definition of a signal sequence is a functional
one. The mature form of the extracellular protein lacks the signal
sequence which is cleaved off during the secretion process. While
the native signal sequence of MauMan1 may be employed in aspects of
the present compositions and methods, other non-native signal
sequences may be employed (e.g., one selected from SEQ ID
NOs:9-37).
[0143] The beta-mannanase polypeptides of the invention may be
referred to as "precursor," "immature," or "full-length," in which
case they include a signal sequence, or may be referred to as
"mature," in which case they lack a signal sequence. Mature forms
of the polypeptides are generally the most useful. Unless otherwise
noted, the amino acid residue numbering used herein refers to the
mature forms of the respective amylase polypeptides. The
beta-mannanase polypeptides of the invention may also be truncated
to remove the N or C-termini, so long as the resulting polypeptides
retain beta-mannanase activity.
[0144] The beta-mannanase polypeptides of the invention may also be
a "chimeric" or "hybrid" polypeptide, in that it includes at least
a portion of a first beta-mannanase polypeptide, and at least a
portion of a second beta-mannanase polypeptide (such chimeric
beta-mannanase polypeptides may, for example, be derived from the
first and second beta-mannanase using known technologies involving
the swapping of domains on each of the beta-mannanase). The present
beta-mannanase polypeptides may further include heterologous signal
sequence, an epitope to allow tracking or purification, or the
like. When the term of "heterologous" is used to refer to a signal
sequence used to express a polypeptide of interest, it is meant
that the signal sequence is, for example, derived from a different
microorganism as the polypeptide of interest. Examples of suitable
heterologous signal sequences for expressing the MauMan1
polypeptides herein, may be, for example, those from Trichoderma
reesei, other Trichoderma spp., Aspergillus niger, Aspergillus
oryzae, other Aspergillus spp., Chrysosporium, and other organisms,
those from Bacillus subtilis, Bacillus licheniformis, other
Bacillus species, E. coli., or other suitable microbes.
[0145] As used herein, "functionally attached" or "operably linked"
means that a regulatory region or functional domain having a known
or desired activity, such as a promoter, terminator, signal
sequence or enhancer region, is attached to or linked to a target
(e.g., a gene or polypeptide) in such a manner as to allow the
regulatory region or functional domain to control the expression,
secretion or function of that target according to its known or
desired activity.
[0146] As used herein, the terms "polypeptide" and "enzyme" are
used interchangeably to refer to polymers of any length comprising
amino acid residues linked by peptide bonds. The conventional
one-letter or three-letter codes for amino acid residues are used
herein. The polymer may be linear or branched, it may comprise
modified amino acids, and it may be interrupted by non-amino acids.
The terms also encompass an amino acid polymer that has been
modified naturally or by intervention; for example, disulfide bond
formation, glycosylation, lipidation, acetylation, phosphorylation,
or any other manipulation or modification, such as conjugation with
a labeling component. Also included within the definition are, for
example, polypeptides containing one or more analogs of an amino
acid (including, for example, unnatural amino acids, etc.), as well
as other modifications known in the art.
[0147] As used herein, "wild-type" and "native" genes, enzymes, or
strains, are those found in nature.
[0148] The terms "wild-type," "parental," or "reference," with
respect to a polypeptide, refer to a naturally-occurring
polypeptide that does not include a man-made substitution,
insertion, or deletion at one or more amino acid positions.
Similarly, the term "wild-type," "parental," or "reference," with
respect to a polynucleotide, refers to a naturally-occurring
polynucleotide that does not include a man-made nucleoside change.
However, a polynucleotide encoding a wild-type, parental, or
reference polypeptide is not limited to a naturally-occurring
polynucleotide, but rather encompasses any polynucleotide encoding
the wild-type, parental, or reference polypeptide.
[0149] As used herein, a "variant polypeptide" refers to a
polypeptide that is derived from a parent (or reference)
polypeptide by the substitution, addition, or deletion, of one or
more amino acids, typically by recombinant DNA techniques. Variant
polypeptides may differ from a parent polypeptide by a small number
of amino acid residues. They may be defined by their level of
primary amino acid sequence homology/identity with a parent
polypeptide. Suitably, variant polypeptides have at least 50%, at
least 55%, at least 60%, at least 65%, at least 70%, at least 75%,
at least 80%, at least 85%, at least 90%, at least 91%, at least
92%, at least 93%, at least 94%, at least 95%, at least 96%, at
least 97%, at least 98%, or even at least 99% amino acid sequence
identity to a parent polypeptide.
[0150] As used herein, a "variant polynucleotide" encodes a variant
polypeptide, has a specified degree of homology/identity with a
parent polynucleotide, or hybridized under stringent conditions to
a parent polynucleotide or the complement thereof. Suitably, a
variant polynucleotide has at least 50%, at least 55%, at least
60%, at least 65%, at least 70%, at least 75%, at least 80%, at
least 85%, at least 90%, at least 91%, at least 92%, at least 93%,
at least 94%, at least 95%, at least 96%, at least 97%, at least
98%, or even at least 99% nucleotide sequence identity to a parent
polynucleotide or to a complement of the parent polynucleotide.
Methods for determining percent identity are known in the art and
described above.
[0151] The term "derived from" encompasses the terms "originated
from," "obtained from," "obtainable from," "isolated from," and
"created from," and generally indicates that one specified material
find its origin in another specified material or has features that
can be described with reference to the another specified
material.
[0152] As used herein, the term "hybridization conditions" refers
to the conditions under which hybridization reactions are
conducted. These conditions are typically classified by degree of
"stringency" of the conditions under which hybridization is
measured. The degree of stringency can be based, for example, on
the melting temperature (Tm) of the nucleic acid binding complex or
probe. For example, "maximum stringency" typically occurs at about
Tm -5.degree. C. (5.degree. C. below the Tm of the probe); "high
stringency" at about 5-10.degree. C. below the Tm; "intermediate
stringency" at about 10-20.degree. C. below the Tm of the probe;
and "low stringency" at about 20-25.degree. C. below the Tm.
Alternatively, or in addition, hybridization conditions can be
based upon the salt or ionic strength conditions of hybridization,
and/or upon one or more stringency washes, e.g.: 6.times.SSC=very
low stringency; 3.times.SSC=low to medium stringency;
1.times.SSC=medium stringency; and 0.5.times.SSC=high stringency.
Functionally, maximum stringency conditions may be used to identify
nucleic acid sequences having strict identity or near-strict
identity with the hybridization probe; while high stringency
conditions are used to identify nucleic acid sequences having about
80% or more sequence identity with the probe. For applications
requiring high selectivity, it is typically desirable to use
relatively stringent conditions to form the hybrids (e.g.,
relatively low salt and/or high temperature conditions are
used).
[0153] As used herein, the term "hybridization" refers to the
process by which a strand of nucleic acid joins with a
complementary strand through base pairing, as known in the art.
More specifically, "hybridization" refers to the process by which
one strand of nucleic acid forms a duplex with, i.e., base pairs
with, a complementary strand, as occurs during blot hybridization
techniques and PCR techniques. A nucleic acid sequence is
considered to be "selectively hybridizable" to a reference nucleic
acid sequence if the two sequences specifically hybridize to one
another under moderate to high stringency hybridization and wash
conditions. Hybridization conditions are based on the melting
temperature (Tm) of the nucleic acid binding complex or probe. For
example, "maximum stringency" typically occurs at about
Tm-5.degree. C. (5.degree. below the Tm of the probe); "high
stringency" at about 5-10.degree. C. below the Tm; "intermediate
stringency" at about 10-20.degree. C. below the Tm of the probe;
and "low stringency" at about 20-25.degree. C. below the Tm.
Functionally, maximum stringency conditions may be used to identify
sequences having strict identity or near-strict identity with the
hybridization probe; while intermediate or low stringency
hybridization can be used to identify or detect polynucleotide
sequence homologs.
[0154] Intermediate and high stringency hybridization conditions
are well known in the art. For example, intermediate stringency
hybridizations may be carried out with an overnight incubation at
37.degree. C. in a solution comprising 20% formamide, 5.times.SSC
(150 mM NaCl, 15 mM trisodium citrate), 50 mM sodium phosphate (pH
7.6), 5.times.Denhardt's solution, 10% dextran sulfate and 20 mg/ml
denatured sheared salmon sperm DNA, followed by washing the filters
in 1.times.SSC at about 37-50.degree. C. High stringency
hybridization conditions may be hybridization at 65.degree. C. and
0.1.times.SSC (where 1.times.SSC=0.15 M NaCl, 0.015 M Na.sub.3
citrate, pH 7.0). Alternatively, high stringency hybridization
conditions can be carried out at about 42.degree. C. in 50%
formamide, 5.times.SSC, 5.times.Denhardt's solution, 0.5% SDS and
100 .mu.g/ml denatured carrier DNA followed by washing two times in
2.times.SSC and 0.5% SDS at room temperature and two additional
times in 0.1.times.SSC and 0.5% SDS at 42.degree. C. And very high
stringent hybridization conditions may be hybridization at
68.degree. C. and 0.1.times.SSC. Those of skill in the art know how
to adjust the temperature, ionic strength, etc. as necessary to
accommodate factors such as probe length and the like.
[0155] A nucleic acid encoding a variant beta-mannase may have a
T.sub.m reduced by 1.degree. C.-3.degree. C. or more compared to a
duplex formed between the nucleotide of SEQ ID NO:1 and its
identical complement.
[0156] The phrase "substantially similar" or "substantially
identical," in the context of at least two nucleic acids or
polypeptides, means that a polynucleotide or polypeptide comprises
a sequence that has at least about 90%, at least about 91%, at
least about 92%, at least about 93%, at least about 94%, at least
about 95%, at least about 96%, at least about 97%, at least about
98%, or even at least about 99% identical to a parent or reference
sequence, or does not include amino acid substitutions, insertions,
deletions, or modifications made only to circumvent the present
description without adding functionality.
[0157] As used herein, an "expression vector" refers to a DNA
construct containing a DNA sequence that encodes a specified
polypeptide and is operably linked to a suitable control sequence
capable of effecting the expression of the polypeptides in a
suitable host. Such control sequences may include a promoter to
effect transcription, an optional operator sequence to control such
transcription, a sequence encoding suitable mRNA ribosome binding
sites and/or sequences that control termination of transcription
and translation. The vector may be a plasmid, a phage particle, or
a potential genomic insert. Once transformed into a suitable host,
the vector may replicate and function independently of the host
genome, or may, in some instances, integrate into the host
genome.
[0158] The term "recombinant," refers to genetic material (i.e.,
nucleic acids, the polypeptides they encode, and vectors and cells
comprising such polynucleotides) that has been modified to alter
its sequence or expression characteristics, such as by mutating the
coding sequence to produce an altered polypeptide, fusing the
coding sequence to that of another gene, placing a gene under the
control of a different promoter, expressing a gene in a
heterologous organism, expressing a gene at a decreased or elevated
levels, expressing a gene conditionally or constitutively in a
manner different from its natural expression profile, and the like.
Generally recombinant nucleic acids, polypeptides, and cells based
thereon, have been manipulated by man such that they are not
identical to related nucleic acids, polypeptides, and cells found
in nature.
[0159] A "signal sequence" refers to a sequence of amino acids
bound to the N-terminal portion of a polypeptide, and which
facilitates the secretion of the mature form of the polypeptide
from the cell. The mature form of the extracellular polypeptide
lacks the signal sequence which is cleaved off during the secretion
process.
[0160] The term "selective marker" or "selectable marker," refers
to a gene capable of expression in a host cell that allows for ease
of selection of those hosts containing an introduced nucleic acid
or vector. Examples of selectable markers include but are not
limited to antimicrobial substances (e.g., hygromycin, bleomycin,
or chloramphenicol) and/or genes that confer a metabolic advantage,
such as a nutritional advantage, on the host cell.
[0161] The term "regulatory element," refers to a genetic element
that controls some aspect of the expression of nucleic acid
sequences. For example, a promoter is a regulatory element which
facilitates the initiation of transcription of an operably linked
coding region. Additional regulatory elements include splicing
signals, polyadenylation signals and termination signals.
[0162] As used herein, "host cells" are generally cells of
prokaryotic or eukaryotic hosts that are transformed or transfected
with vectors constructed using recombinant DNA techniques known in
the art. Transformed host cells are capable of either replicating
vectors encoding the polypeptide variants or expressing the desired
polypeptide variant. In the case of vectors, which encode the pre-
or pro-form of the polypeptide variant, such variants, when
expressed, are typically secreted from the host cell into the host
cell medium.
[0163] The term "introduced," in the context of inserting a nucleic
acid sequence into a cell, means transformation, transduction, or
transfection. Means of transformation include protoplast
transformation, calcium chloride precipitation, electroporation,
naked DNA, and the like as known in the art. (See, Chang and Cohen
(1979) Mol. Gen. Genet. 168:111-115; Smith et al., (1986) Appl.
Env. Microbiol. 51:634; and the review article by Ferrari et al.,
in Harwood, Bacillus, Plenum Publishing Corporation, pp. 57-72,
1989).
[0164] "Fused" polypeptide sequences are connected, i.e., operably
linked, via a peptide bond between two subject polypeptide
sequences.
[0165] The term "filamentous fungi" refers to all filamentous forms
of the subdivision Eumycotina, particularly Pezizomycotina
species.
[0166] Other technical and scientific terms have the same meaning
as commonly understood by one of ordinary skill in the art to which
this disclosure pertains (See, e.g., Singleton and Sainsbury,
Dictionary of Microbiology and Molecular Biology, 2d Ed., John
Wiley and Sons, NY 1994; and Hale and Marham, The Harper Collins
Dictionary of Biology, Harper Perennial, NY 1991).
[0167] The beta-mannanase enzyme MauMan1 from Mahella australiensis
50-1 BON (SEQ ID NO:2) has the following amino acid sequence:
TABLE-US-00001 NETKAAPSIASTGIDVSSLK
GVNHAHTWYPDRLVQALQGIQSWGANSVRVVLSNGCKWAKNSASDVANV
ISKAQQLGFTAVILEVHDTTGYGEDSSACSLNDAVAYWKEIQSVLIGKE
DFVIINIGNEPYGNNNYQNWTQDTIDAINALREAGFNHTIMVDAPNWGQ
DWSFTMRDNAPKVYAADPNKNMVFSIHMYGVYNTAQKVHDYFQAFKDMN
LPLVVGEFGNQHSDGDPDEEAIVSYAKQYGIGYLGWSWCGNSGGVEYLD
MVNNWDANSPTSWGNWFKTNALAEITPPSDTTPPAAPTGLTATAVSSSS
INLDWADNTDSDLAGYKVYRSTFSGFTPSSANFAKQVTSSAYTDTGLTA
DTTYYYKVTAVDTSGNESQPSAQASAKTQQGGGTTPPGEYTEITLPFTH
DGAGEYYWKTNKLSTDPNDWSHYINSWNLDLLEINGKNYTNVWVAQHQI
APLSDGYWYIHCKGGFSYSHVEIK
[0168] The mature beta-mannanase enzyme, as based on the removal of
the predicted signal peptide sequence of SEQ ID NO:3:
TABLE-US-00002 NETKAAPSIASTGIDVSSLKGVNHAHTWYPDRLVQALQGIQSWGANSV
RVVLSNGCKWAKNSASDVANVISKAQQLGFTAVILEVHDTTGYGEDSS
ACSLNDAVAYWKEIQSVLIGKEDFVIINIGNEPYGNNNYQNWTQDTID
AINALREAGFNHTIMVDAPNWGQDWSFTMRDNAPKVYAADPNKNMVFS
IHMYGVYNTAQKVHDYFQAFKDMNLPLVVGEFGNQHSDGDPDEEAIVS
YAKQYGIGYLGWSWCGNSGGVEYLDMVNNWDANSPTSWGNWFKTNALA
EITPPSDTTPPAAPTGLTATAVSSSSINLDWADNTDSDLAGYKVYRST
FSGFTPSSANFAKQVTSSAYTDTGLTADTTYYYKVTAVDTSGNESQPS
AQASAKTQQGGGTTPPGEYTEITLPFTHDGAGEYYWKTNKLSTDPNDW
SHYINSWNLDLLEINGKNYTNVWVAQHQIAPLSDGYWYIHCKGGFSYS HVEIK
[0169] A number of other bacterial beta-mannanases having similar
pH optimums and/or temperature optimums have been used as benchmark
molecules herein, including a beta-mannanase of
Caldicellulosiruptor hydrothermalis, called "ChyMan1" herein,
having the following amino acid sequence (SEQ ID NO: 4):
TABLE-US-00003 VETSVQSYVFDFEDGTTMTFDEAWGDSLKCIKKVSVSTDLQRPGNKYAL
RLDVEFNENNGWDQGDLGAWIGGVVEGQFDFTNYKSVEFEMFVPYDEFA
KAKGGFAYKVVLNDGWKELGSEFSITVNAGKKVKINGKDYMVIHKAFAI
PDDFRTKKRAQLVFQFAGQNCNYKGPIYLDNIRIRPEDASNLSKEDYGS
SEEEEIVENFFTGVTLVYPVEGKNFVYNFEKDTMGFYKYSGDGFAKKTK
SMEFSQDLKTSTNAGSLKLNANFQGTAFEEMNIAVKLTDKEGKLFDLGK
YSTLEYTIYIPNPDKVAGKIMSASAVDSPWKIIKDFTALNYKDKTTWKE
INGKTYAVIKCKDNLYNVREKAGVLVLRIAGSYVKYTGPIYIDNVALIA
GKKVAPKVERISLPNPKTYYKVKIEAESASDGWAYSVEKENAKFSGKGY
VLLFGNNMGNTLYNIKVPKTGHYIFTLAISTLGLVKDGSIDIWIDGDLK
GGAKVPNVKGKFQEVVVRKKIYLTEGEHTISLQKSGGYTIAVDYFVIEE
LVAANKSKLSVSSKLVTPNPHPNAQRLMNYLASIYGEKILSGQQSSGEG
KEVQMIFDVTRRYPAVRSFDLMDYSPSRMQRGTKGTDVDEAIKWWKNGG
IVAFCWHWNAPTGLIDQPGKEWWRGFYTEATTFDLKKAMDNPNSEEYKL
ILRDIDAIAQQFKKLQAEGVPVLFRPLHEASGGWFWWGAKGAEPYIKLW
KLMFDRLVNYHKVNNLIWVWNGQDAAWYPGDQYVDIIAEDIYEEKAQYS
PYTERFVKALKYTNSNKMIALSECGTIPDPAVLKQEGVSWLWFSVWAGG
YVMTGSKYNDEWNDNHMLRKIYNSDYVITKDELPDIKSIPLE
[0170] Benchmark beta-mannanases also include a GH5 beta-mannanase
TceMan1 from Thermobifida cellulosilytica, having the following
amino acid sequence (SEQ ID NO:5):
TABLE-US-00004 ATGIHVRNGRIYEANGQEFVMRGVSHAHTWYPQHTRAFADIKSHGANTV
RVVLSNGVRWSKNGPSDVADIISLCKQNRLICMLEVHDTTGYGEQSGAA
TLDQAVDYWIELKSVLQGQEDYVLINIGNEPYGNNAATVANWASDTSAA
IRRLRAAGFEHAIVVDAPNWGQDWSHTMRTNAADVYASDPTGNTIFSIH
MYGVYSQGSTVTSYLEHFVNAGLPLVIGEFGHDHSDGNPDEDTIMAEAE
RLGLGYIGWSWSGNGGGVEYLDMVDNFDGDSLTSWGRRIFYGPNGISGT
AREATVYSGDPGTDPGTDPGTDPGTDPGTDPGTGACSAAYTTVGDWGSG
FQGEVTVTAGSSAISHWKVTWTFPGGQSVSHGWNAAFNGSSSVTATSLS
YNGQLGAGQSTAFGFIGSGSAPGALTLTCSVD
Beta-Mannanase Polypeptides, Polynucleotides, Vectors, and Host
Cells
MauMan1 Polypeptides
[0171] In one aspect, the present compositions and methods provide
a recombinant MauMan1 beta-mannanase polypeptide, fragments
thereof, or variants thereof having beta-mannanase activity. An
example of a recombinant beta-mannanase polypeptide was isolated
from Mahella australiensis. The mature MauMan1 polypeptide has the
amino acid sequence set forth as SEQ ID NO:3. Similar,
substantially similar MauMan1 polypeptides may occur in nature,
e.g., in other strains or isolates of Mahella australiensis, or
Mahella spp. These and other recombinant MauMan1 polypeptides are
encompassed by the present compositions and methods.
[0172] In some embodiments, the recombinant MauMan1 polypeptide is
a variant MauMan1 polypeptide having a specified degree of amino
acid sequence identity to the exemplified MauMan1 polypeptide,
e.g., at least 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%,
93%, 94%, 95%, 96%, 97%, 98%, or even at least 99% sequence
identity to the amino acid sequence of SEQ ID NO:2 or to the mature
sequence SEQ ID NO:3. Sequence identity can be determined by amino
acid sequence alignment, e.g., using a program such as BLAST,
ALIGN, or CLUSTAL, as described herein.
[0173] In certain embodiments, the recombinant MauMan1 polypeptides
are produced recombinantly, in a microorganism, for example, in a
bacterial or fungal host organism, while in others the MauMan1
polypeptides are produced synthetically, or are purified from a
native source (e.g., Mahella australiensis).
[0174] In certain embodiments, the recombinant MauMan1 polypeptide
includes substitutions that do not substantially affect the
structure and/or function of the polypeptide. Examples of these
substitutions are conservative mutations, as summarized in Table
I.
TABLE-US-00005 TABLE I Amino Acid Substitutions Original Residue
Code Acceptable Substitutions Alanine A D-Ala, Gly, beta-Ala,
L-Cys, D-Cys Arginine R D-Arg, Lys, D-Lys, homo-Arg, D-homo-Arg,
Met, Ile, D-Met, D-Ile, Orn, D-Orn Asparagine N D-Asn, Asp, D-Asp,
Glu, D-Glu, Gln, D-Gln Aspartic Acid D D-Asp, D-Asn, Asn, Glu,
D-Glu, Gln, D-Gln Cysteine C D-Cys, S--Me-Cys, Met, D-Met, Thr,
D-Thr Glutamine Q D-Gln, Asn, D-Asn, Glu, D-Glu, Asp, D-Asp
Glutamic Acid E D-Glu, D-Asp, Asp, Asn, D-Asn, Gln, D-Gln Glycine G
Ala, D-Ala, Pro, D-Pro, beta-Ala, Acp Isoleucine I D-Ile, Val,
D-Val, Leu, D-Leu, Met, D-Met Leucine L D-Leu, Val, D-Val, Leu,
D-Leu, Met, D-Met Lysine K D-Lys, Arg, D-Arg, homo-Arg, D-homo-Arg,
Met, D-Met, Ile, D-Ile, Orn, D-Orn Methionine M D-Met, S--Me-Cys,
Ile, D-Ile, Leu, D-Leu, Val, D-Val Phenylalanine F D-Phe, Tyr,
D-Thr, L-Dopa, His, D-His, Trp, D-Trp, Trans-3,4, or
5-phenylproline, cis-3,4, or 5-phenylproline Proline P D-Pro,
L-I-thioazolidine-4-carboxylic acid, D-or
L-1-oxazolidine-4-carboxylic acid Serine S D-Ser, Thr, D-Thr,
allo-Thr, Met, D-Met, Met(O), D-Met(O), L-Cys, D-Cys Threonine T
D-Thr, Ser, D-Ser, allo-Thr, Met, D-Met, Met(O), D-Met(O), Val,
D-Val Tyrosine Y D-Tyr, Phe, D-Phe, L-Dopa, His, D-His Valine V
D-Val, Leu, D-Leu, Ile, D-Ile, Met, D-Met
[0175] Substitutions involving naturally occurring amino acids are
generally made by mutating a nucleic acid encoding a recombinant
MauMan1 polypeptide, and then expressing the variant polypeptide in
an organism. Substitutions involving non-naturally occurring amino
acids or chemical modifications to amino acids are generally made
by chemically modifying a MauMan1 polypeptide after it has been
synthesized by an organism.
[0176] In some embodiments, variant recombinant MauMan1
polypeptides are substantially identical to SEQ ID NO:2 or SEQ ID
NO:3, meaning that they do not include amino acid substitutions,
insertions, or deletions that do not significantly affect the
structure, function, or expression of the polypeptide. Such variant
recombinant MauMan1 polypeptides will include those designed to
circumvent the present description. In some embodiments, variants
recombinant MauMan1 polypeptides, compositions and methods
comprising these variants are not substantially identical to SEQ ID
NO:2 or SEQ ID NO:3, but rather include amino acid substitutions,
insertions, or deletions that affect, in certain circumstances,
substantially, the structure, function, or expression of the
polypeptide herein such that improved characteristics, including,
e.g., improved specific activity to hydrolyze a mannan-containing
lignocellulosic substrate, more rapid viscosity reduction when used
to treat high solids biomass substrates, improved expression in a
desirable host organism, improved thermostability, pH stability,
etc, as compared to that of a polypeptide of SEQ ID NO:2 or SEQ ID
NO:3 can be achieved.
[0177] In some embodiments, the recombinant MauMan1 polypeptide
(including a variant thereof) has beta-mannanase activity.
Beta-mannanase activity can be determined using an assay measuring
the release of reducing sugars from a galactomannan substrate, for
example, in accordance with the description of Example 5.
Beta-mannanase activity can be determined by combining with a
cellulase and/or hemicellulase mixture, followed by using such a
mixture to treat a suitable mannan-containing biomass substrate,
such as, for example, a woody substrate, etc., in accordance with
the protocols and conditions described in, for example, Example 9,
or by suitable assays, or methods of activity measurement known in
the art.
[0178] Recombinant MauMan1 polypeptides include fragments of
"full-length" MauMan1 polypeptides that retain beta-mannanase
activity. Preferably those functional fragments (i.e., fragments
that retain beta-mannanase activity) are at least 80 amino acid
residues in length (e.g., at least 80 amino acid residues, at least
100 amino acid residues, at least 120 amino acid residues, at least
140 amino acid residues, at least 160 amino acid residues, at least
180 amino acid residues, at least 200 amino acid residues, at least
220 amino acid residues, at least 240 amino acid residues, at least
260 amino acid residues, at least 280 amino acid residues, at least
300 amino acid residues, at least 350 amino acid residues, at least
400 amino acid residues, or even at least 4amino acid residues in
length or longer). Such fragments suitably retain the active site
of the full-length precursor polypeptides or full length mature
polypeptides but may have deletions of non-critical amino acid
residues. The activity of fragments can be readily determined using
the methods of measuring beta-mannanase activity described herein,
for example the assay described in Example 5, and the hydrolysis
performance measurements as those described in Example 9, or by
suitable assays or other means of activity measurements known in
the art.
[0179] In some embodiments, the MauMan1 amino acid sequences and
derivatives are produced as an N- and/or C-terminal fusion protein,
for example, to aid in extraction, detection and/or purification
and/or to add functional properties to the MauMan1 polypeptides.
Examples of fusion protein partners include, but are not limited
to, glutathione-S-transferase (GST), 6.times.His, GAL4 (DNA binding
and/or transcriptional activation domains), FLAG-, MYC-tags or
other tags known to those skilled in the art. In some embodiments,
a proteolytic cleavage site is provided between the fusion protein
partner and the polypeptide sequence of interest to allow removal
of fusion sequences. Suitably, the fusion protein does not hinder
the activity of the recombinant MauMan1 polypeptide. In some
embodiments, the recombinant MauMan1 polypeptide is fused to a
functional domain including a leader peptide, propeptide, binding
domain and/or catalytic domain. Fusion proteins are optionally
linked to the recombinant MauMan1 polypeptide through a linker
sequence that joins the MauMan1 polypeptide and the fusion domain
without significantly affecting the properties of either component.
The linker optionally contributes functionally to the intended
application.
[0180] The present disclosure provides host cells that are
engineered to express one or more MauMan1 polypeptides of the
disclosure. Suitable host cells include cells of any microorganism
(e.g., cells of a bacterium, a protist, an alga, a fungus (e.g., a
yeast or filamentous fungus), or other microbe), and are preferably
cells of a bacterium, a yeast, or a filamentous fungus.
[0181] Suitable host cells of the bacterial genera include, but are
not limited to, cells of Escherichia, Bacillus, Lactobacillus,
Pseudomonas, and Streptomyces. Suitable cells of bacterial species
include, but are not limited to, cells of Escherichia coli,
Bacillus subtilis, Bacillus licheniformis, Lactobacillus brevis,
Pseudomonas aeruginosa, and Streptomyces lividans.
[0182] Suitable host cells of the genera of yeast include, but are
not limited to, cells of Saccharomyces, Schizosaccharomyces,
Candida, Hansenula, Pichia, Kluyveromyces, and Phaffia. Suitable
cells of yeast species include, but are not limited to, cells of
Saccharomyces cerevisiae, Schizosaccharomyces pombe, Candida
albicans, Hansenula polymorpha, Pichia pastoris, P. canadensis,
Kluyveromyces marxianus, and Phaffia rhodozyma.
[0183] Suitable host cells of filamentous fungi include all
filamentous forms of the subdivision Eumycotina. Suitable cells of
filamentous fungal genera include, but are not limited to, cells of
Acremonium, Aspergillus, Aureobasidium, Bjerkandera, Ceriporiopsis,
Chrysoporium, Coprinus, Coriolus, Corynascus, Chaertomium,
Cryptococcus, Filobasidium, Fusarium, Gibberella, Humicola,
Magnaporthe, Mucor, Myceliophthora, Mucor, Neocallimastix,
Neurospora, Paecilomyces, Penicillium, Phanerochaete, Phlebia,
Piromyces, Pleurotus, Scytaldium, Schizophyllum, Sporotrichum,
Talaromyces, Thermoascus, Thielavia, Tolypocladium, Trametes, and
Trichoderma.
[0184] Suitable cells of filamentous fungal species include, but
are not limited to, cells of Aspergillus awamori, Aspergillus
fumigatus, Aspergillus foetidus, Aspergillus japonicus, Aspergillus
nidulans, Aspergillus niger, Aspergillus oryzae, Chrysosporium
lucknowense, Fusarium bactridioides, Fusarium cerealis, Fusarium
crookwellense, Fusarium culmorum, Fusarium graminearum, Fusarium
graminum, Fusarium heterosporum, Fusarium negundi, Fusarium
oxysporum, Fusarium reticulatum, Fusarium roseum, Fusarium
sambucinum, Fusarium sarcochroum, Fusarium sporotrichioides,
Fusarium sulphureum, Fusarium torulosum, Fusarium trichothecioides,
Fusarium venenatum, Bjerkandera adusta, Ceriporiopsis aneirina,
Ceriporiopsis aneirina, Ceriporiopsis caregiea, Ceriporiopsis
gilvescens, Ceriporiopsis pannocinta, Ceriporiopsis rivulosa,
Ceriporiopsis subrufa, Ceriporiopsis subvermispora, Coprinus
cinereus, Coriolus hirsutus, Humicola insolens, Humicola
lanuginosa, Mucor miehei, Myceliophthora thermophila, Neurospora
crassa, Neurospora intermedia, Penicillium purpurogenum,
Penicillium canescens, Penicillium solitum, Penicillium funiculosum
Phanerochaete chrysosporium, Phlebia radiate, Pleurotus eryngii,
Talaromyces flavus, Thielavia terrestris, Trametes villosa,
Trametes versicolor, Trichoderma harzianum, Trichoderma koningii,
Trichoderma longibrachiatum, Trichoderma reesei, and Trichoderma
viride.
[0185] Methods of transforming nucleic acids into these organisms
are known in the art. For example, a suitable procedure for
transforming Aspergillus host cells is described in EP 238 023.
[0186] In some embodiments, the recombinant MauMan1 polypeptide is
fused to a signal peptide to, for example, facilitate extracellular
secretion of the recombinant MauMan1 polypeptide. For example, in
certain embodiments, the signal peptide is a non-native signal
peptide such as the B. subtilis AprE signal peptide of SEQ ID NO:9.
In some embodiments, the MauMan1 polypeptide has an N-terminal
extension of Ala-Gly-Lys between the mature form and the signal
polypeptide. In particular embodiments, the recombinant MauMan1
polypeptide is expressed in a heterologous organism as a secreted
polypeptide. The compositions and methods herein thus encompass
methods for expressing a MauMan1 polypeptide as a secreted
polypeptide in a heterologous organism.
[0187] The disclosure also provides expression cassettes and/or
vectors comprising the above-described nucleic acids. Suitably, the
nucleic acid encoding a MauMan1 polypeptide of the disclosure is
operably linked to a promoter. Promoters are well known in the art.
Any promoter that functions in the host cell can be used for
expression of a beta-mannanase and/or any of the other nucleic
acids of the present disclosure. Initiation control regions or
promoters, which are useful to drive expression of a beta-mannanase
nucleic acids and/or any of the other nucleic acids of the present
disclosure in various host cells are numerous and familiar to those
skilled in the art (see, for example, WO 2004/033646 and references
cited therein). Virtually any promoter capable of driving these
nucleic acids can be used.
[0188] Specifically, where recombinant expression in a filamentous
fungal host is desired, the promoter can be a filamentous fungal
promoter. The nucleic acids can be, for example, under the control
of heterologous promoters. The nucleic acids can also be expressed
under the control of constitutive or inducible promoters. Examples
of promoters that can be used include, but are not limited to, a
cellulase promoter, a xylanase promoter, the 1818 promoter
(previously identified as a highly expressed protein by EST mapping
Trichoderma). For example, the promoter can suitably be a
cellobiohydrolase, endoglucanase, or beta-glucosidase promoter. A
particularly suitable promoter can be, for example, a T. reesei
cellobiohydrolase, endoglucanase, or beta-glucosidase promoter. For
example, the promoter is a cellobiohydrolase I (cbh1) promoter.
Non-limiting examples of promoters include a cbh1, cbh2, egl1,
egl2, egl3, egl4, egl5, pki1, gpd1, xyn1, or xyn2 promoter.
Additional non-limiting examples of promoters include a T. reesei
cbh1, cbh2, egl1, egl2, egl3, egl4, egl5, pki1, gpd1, xyn1, or xyn2
promoter.
[0189] The nucleic acid sequence encoding a MauMan1 polypeptide
herein can be included in a vector. In some aspects, the vector
contains the nucleic acid sequence encoding the MauMan1 polypeptide
under the control of an expression control sequence. In some
aspects, the expression control sequence is a native expression
control sequence. In some aspects, the expression control sequence
is a non-native expression control sequence. In some aspects, the
vector contains a selective marker or selectable marker. In some
aspects, the nucleic acid sequence encoding the MauMan1 polypeptide
is integrated into a chromosome of a host cell without a selectable
marker.
[0190] Suitable vectors are those which are compatible with the
host cell employed. Suitable vectors can be derived, for example,
from a bacterium, a virus (such as bacteriophage T7 or a M-13
derived phage), a cosmid, a yeast, or a plant. Suitable vectors can
be maintained in low, medium, or high copy number in the host cell.
Protocols for obtaining and using such vectors are known to those
in the art (see, for example, Sambrook et al., Molecular Cloning: A
Laboratory Manual, 2.sup.nd ed., Cold Spring Harbor, 1989).
[0191] In some aspects, the expression vector also includes a
termination sequence. Termination control regions may also be
derived from various genes native to the host cell. In some
aspects, the termination sequence and the promoter sequence are
derived from the same source.
[0192] A nucleic acid sequence encoding a MauMan1 polypeptide can
be incorporated into a vector, such as an expression vector, using
standard techniques (Sambrook et al., Molecular Cloning: A
Laboratory Manual, Cold Spring Harbor, 1982).
[0193] In some aspects, it may be desirable to over-express a
MauMan1 polypeptide and/or one or more of any other nucleic acid
described in the present disclosure at levels far higher than
currently found in naturally-occurring cells. In some embodiments,
it may be desirable to under-express (e.g., mutate, inactivate, or
delete) an endogenous beta-mannanase and/or one or more of any
other nucleic acid described in the present disclosure at levels
far below that those currently found in naturally-occurring
cells.
MauMan1-Encoding Polynucleotides
[0194] Another aspect of the compositions and methods described
herein is a polynucleotide or a nucleic acid sequence that encodes
a recombinant MauMan1 polypeptide (including variants and fragments
thereof) having beta-mannanase activity. In some embodiments the
polynucleotide is provided in the context of an expression vector
for directing the expression of a MauMan1 polypeptide in a
heterologous organism, such as one identified herein. The
polynucleotide that encodes a recombinant MauMan1 polypeptide may
be operably-linked to regulatory elements (e.g., a promoter,
terminator, enhancer, and the like) to assist in expressing the
encoded polypeptides.
[0195] An example of a polynucleotide sequence encoding a
recombinant MauMan1 polypeptide has the nucleotide sequence of SEQ
ID NO: 1. Similar, including substantially identical,
polynucleotides encoding recombinant MauMan1 polypeptides and
variants may occur in nature, e.g., in other strains or isolates of
Mahella australiensis, or Mahella sp. In view of the degeneracy of
the genetic code, it will be appreciated that polynucleotides
having different nucleotide sequences may encode the same MauMan1
polypeptides, variants, or fragments.
[0196] In some embodiments, polynucleotides encoding recombinant
MauMan1 polypeptides have a specified degree of amino acid sequence
identity to the exemplified polynucleotide encoding a MauMan1
polypeptide, e.g., at least 55%, at last 60%, at least 65%, at
least 70%, at least 75%, at least 80%, at least 85%, at least 86%,
at least 87%, at least 88%, at least 89%, at least 90%, at least
91%, at least 92%, at least 93%, at least 94%, at least 95%, at
least 96%, at least 97%, at least 98%, or even at least 99%
sequence identity to the amino acid sequence of SEQ ID NO: 2, or to
the mature sequence of SEQ ID NO:3. Homology can be determined by
amino acid sequence alignment, e.g., using a program such as BLAST,
ALIGN, or CLUSTAL, as described herein.
[0197] In some embodiments, the polynucleotide that encodes a
recombinant MauMan1 polypeptide is fused in frame behind (i.e.,
downstream of) a coding sequence for a signal peptide for directing
the extracellular secretion of a recombinant MauMan1 polypeptide.
As described herein, the term "heterologous" when used to refer to
a signal sequence used to express a polypeptide of interest, it is
meant that the signal sequence and the polypeptide of interest are
from different organisms. Heterologous signal sequences include,
for example, those from other fungal cellulase genes, such as,
e.g., the signal sequence of Trichoderma reesei CBH1. Expression
vectors may be provided in a heterologous host cell suitable for
expressing a recombinant MauMan1 polypeptide, or suitable for
propagating the expression vector prior to introducing it into a
suitable host cell.
[0198] In some embodiments, polynucleotides encoding recombinant
MauMan1 polypeptides hybridize to the polynucleotide of SEQ ID NO:1
(or to the complement thereof) under specified hybridization
conditions. Examples of conditions are intermediate stringency,
high stringency and extremely high stringency conditions, which are
described herein.
[0199] MauMan1 polynucleotides may be naturally occurring or
synthetic (i.e., man-made), and may be codon-optimized for
expression in a different host, mutated to introduce cloning sites,
or otherwise altered to add functionality.
[0200] The nucleic acid sequence encoding the coding region of
MauMan1 polypeptide derived from Mahella australiensis 50-1 BON is
as follows (SEQ ID NO: 1), wherein the nucleic acid sequence
encoding the predicted signal peptide sequence is italicized:
TABLE-US-00006 AATGAAA
CTAAAGCGGCTCCTTCGATCGCATCTACAGGTATAGATGTGAGCAGTT
TAAAAGGGGTTAATCATGCACATACCTGGTATCCAGATAGGCTGGTTC
AAGCTCTGCAAGGCATTCAGTCATGGGGAGCCAATTCTGTGAGAGTTG
TCTTAAGTAATGGATGCAAGTGGGCAAAAAATAGTGCTAGTGATGTAG
CAAATGTGATATCTAAAGCTCAACAGCTCGGTTTTACAGCAGTTATAT
TGGAAGTGCACGATACTACAGGATATGGAGAAGACAGCTCAGCTTGTT
CGCTTAATGATGCCGTAGCCTATTGGAAAGAAATTCAGAGCGTTCTTA
TAGGTAAAGAAGACTTCGTTATAATAAATATAGGTAATGAACCATATG
GAAATAATAATTATCAAAACTGGACACAGGATACTATTGATGCTATCA
ATGCGTTAAGAGAAGCAGGATTTAATCATACTATCATGGTAGATGCAC
CGAACTGGGGACAGGATTGGTCATTTACAATGAGGGATAATGCTCCAA
AGGTATATGCAGCGGATCCGAATAAAAACATGGTGTTTTCTATCCACA
TGTATGGGGTTTATAACACGGCTCAAAAAGTGCATGATTATTTCCAAG
CATTCAAAGATATGAATTTACCTCTGGTAGTTGGTGAATTTGGAAACC
AGCATTCCGACGGAGATCCTGATGAAGAAGCTATAGTGAGCTATGCAA
AACAGTATGGTATTGGATACCTTGGTTGGTCATGGTGCGGTAATAGCG
GTGGTGTGGAGTATCTCGATATGGTAAATAATTGGGATGCGAACAGCC
CTACTTCTTGGGGAAACTGGTTTAAAACCAATGCTCTTGCAGAAATTA
CGCCGCCGTCGGACACCACACCACCTGCAGCACCTACAGGATTGACGG
CCACAGCCGTAAGTTCGAGCAGCATAAACCTCGATTGGGCTGATAATA
CGGACAGCGACCTGGCCGGATATAAAGTATACAGAAGCACGTTCAGCG
GTTTCACACCTAGTAGCGCCAACTTCGCGAAGCAGGTAACAAGCAGCG
CTTACACCGATACGGGCTTGACTGCCGATACAACGTATTACTATAAGG
TGACGGCAGTAGATACCAGCGGCAATGAATCACAACCATCGGCACAGG
CCAGCGCTAAAACACAACAAGGTGGAGGTACAACACCGCCGGGAGAAT
ATACTGAGATTACTTTACCGTTTACCCACGACGGAGCAGGGGAATATT
ACTGGAAGACAAATAAACTTTCCACTGATCCCAATGACTGGAGCCACT
ATATAAACTCGTGGAATCTCGATCTTCTTGAGATCAACGGAAAAAACT
ACACCAATGTATGGGTGGCACAACACCAGATAGCACCTTTGTCAGACG
GTTACTGGTATATTCACTGCAAAGGGGGTTTCTCATACTCTCATGTAG AGATTAAGTAA
[0201] As is well known to those of ordinary skill in the art, due
to the degeneracy of the genetic code, polynucleotides having
significantly different sequences can nonetheless encode identical,
or nearly identical, polypeptides. As such, aspects of the present
compositions and methods include polynucleotides encoding MauMan1
polypeptides or derivatives thereof that contain a nucleic acid
sequence that is at least 55% identical to SEQ ID NO: 1, including
at least 55%, at least 60%, at least 70%, at least 75%, at least
80%, at least 81%, at least 82%, at least 83%, at least 84%, at
least 85%, at least 86%, at least 87%, at least 88%, at least 89%,
at least 90%, at least 91%, at least 92%, at least 93%, at least
94%, at least 95%, at least 96%, at least 97%, at least 98%, or at
least 99% identical to SEQ ID NO:1. In some embodiments, MauMan1
polypeptides contain a nucleic acid sequence that is identical to
SEQ ID NO: 1.
[0202] In some embodiments, polynucleotides may include a sequence
encoding a signal peptide. Many convenient signal sequences may be
suitably employed.
Purification from Natural Isolates
[0203] The MauMan1 polypeptides can be purified from natural
isolates (e.g., from a strain of Mahella australiensis) by known
and commonly employed methods. For example, cells containing a
MauMan1 polypeptide can be disrupted by various physical or
chemical means, such as freeze-thaw cycling, sonication, mechanical
disruption, or cell lysing agents. Cell supernatants may be
collected (for example from cells that secrete the protein into the
medium). The MauMan1 polypeptide can be recovered from the medium
and/or lysate by conventional techniques including separations of
the cells/debris from the medium by centrifugation, filtration, and
precipitation of the proteins in the supernatant or filtrate with a
salt, for example, ammonium sulphate. The MauMan1 polypeptide can
then be purified from the disrupted cells by procedures such as:
fractionation on an ion-exchange column; ethanol precipitation;
reverse phase HPLC; chromatography on silica or on a
cation-exchange resin such as DEAE; chromatofocusing; SDS-PAGE;
ammonium sulfate precipitation; gel filtration using, for example,
Sephadex G-75; and affinity chromatography. Various methods of
protein purification may be employed and such methods are known in
the art and described for example in Deutscher, Methods in
Enzymology, 182 (1990); Scopes, Protein Purification: Principles
and Practice, Springer-Verlag, New York (1982).
Chemical Synthesis
[0204] Alternatively, the MauMan1 polypeptide sequence, or portions
thereof, may be produced by direct peptide synthesis using
solid-phase techniques (see, e.g., Stewart et al., Solid-Phase
Peptide Synthesis, W.H. Freeman Co., San Francisco, Calif. (1969);
Merrifield, J. Am. Chem. Soc., 85:2149-2154 (1963)). In vitro
protein synthesis may be performed using manual techniques or by
automation. Automated synthesis may be accomplished, for instance,
using an Applied Biosystems Peptide Synthesizer (Foster City,
Calif.) using manufacturer's instructions. Various portions of
MauMan1 may be chemically synthesized separately and combined using
chemical or enzymatic methods to produce a full-length MauMan1.
Recombinant Methods of Making
Isolation of DNA Encoding the MauMan1 Polypeptide
[0205] DNA encoding a MauMan1 polypeptide may be obtained from a
cDNA library prepared from a microorganism believed to possess the
MauMan1 mRNA (e.g., Mahella australiensis) and to express it at a
detectable level. The MauMan1-encoding gene may also be obtained
from a genomic library or by oligonucleotide synthesis.
[0206] Libraries can be screened with probes (such as antibodies to
a MauMan1 or oligonucleotides of at least about 20-80 bases)
designed to identify the gene of interest or the protein encoded by
it. Screening the cDNA or genomic library with the selected probe
may be conducted using standard procedures, such as described in
Sambrook et al., Molecular Cloning: A Laboratory Manual (New York:
Cold Spring Harbor Laboratory Press, 1989). An alternative means to
isolate the gene encoding a MauMan1 is to use PCR methodology
(Sambrook et al., supra; Dieffenbach et al., PCR Primer: A
Laboratory Manual (Cold Spring Harbor Laboratory Press, 1995)).
[0207] In known techniques for screening a cDNA library, the
oligonucleotide sequences selected as probes should be of
sufficient length and sufficiently unambiguous that false positives
are minimized. The oligonucleotide can be labeled such that it can
be detected upon hybridization to DNA in the library being
screened. Methods of labeling are well known in the art, and
include the use of radiolabels like .sup.32P-labeled ATP,
biotinylation or enzyme labeling. Hybridization conditions,
including moderate stringency and high stringency, are provided in
Sambrook et al., Molecular Cloning: A Laboratory Manual (New York:
Cold Spring Harbor Laboratory Press, 1989).
[0208] Nucleic acids having protein coding sequence may be obtained
by screening selected cDNA or genomic libraries using the deduced
amino acid sequence disclosed herein for the first time, and, if
necessary, using conventional primer extension procedures as
described in Sambrook et al., Molecular Cloning: A Laboratory
Manual (New York: Cold Spring Harbor Laboratory Press, 1989), to
detect precursors and processing intermediates of mRNA that may not
have been reverse-transcribed into cDNA.
Selection and Transformation of Host Cells
[0209] Host cells are transfected or transformed with expression or
cloning vectors described herein for MauMan1 production. The host
cells are cultured in conventional nutrient media modified as
appropriate for inducing promoters, selecting transformants, or
amplifying the genes encoding the desired sequences. The culture
conditions, such as media, temperature, pH and the like, can be
selected by the ordinarily skilled artisan without undue
experimentation. In general, principles, protocols, and practical
techniques for maximizing the productivity of cell cultures can be
found in Mammalian Cell Biotechnology: a Practical Approach, M.
Butler, ed. (IRL Press, 1991) and Sambrook et al., Molecular
Cloning: A Laboratory Manual (New York: Cold Spring Harbor
Laboratory Press, 1989).
[0210] Methods of transfection are known to the ordinarily skilled
artisan, for example, CaPO.sub.4 and electroporation. Depending on
the host cell used, transformation is performed using standard
techniques appropriate to such cells. The calcium treatment
employing calcium chloride, as described in Sambrook et al.,
Molecular Cloning: A Laboratory Manual (New York: Cold Spring
Harbor Laboratory Press, 1989), or electroporation is generally
used for prokaryotes or other cells that contain substantial
cell-wall barriers. Infection with Agrobacterium tumefaciens is
used for transformation of certain plant cells, as described by
Shaw et al., Gene, 23:315 (1983) and WO 89/05859 published 29 Jun.
1989. Transformations into yeast can be carried out according to
the method of Van Solingen et al., J. Bact., 130:946 (1977) and
Hsiao et al., Proc. Natl. Acad. Sci. (USA), 76:3829 (1979).
However, other methods for introducing DNA into cells, such as by
nuclear microinjection, electroporation, microporation, biolistic
bombardment, bacterial protoplast fusion with intact cells, or
polycations, e.g., polybrene, polyornithine, may also be used.
[0211] Suitable host cells for cloning or expressing the DNA in the
vectors herein include prokaryote, yeast, or filamentous fungal
cells. Suitable prokaryotes include but are not limited to
eubacteria, such as Gram-negative or Gram-positive organisms, for
example, Enterobacteriaceae such as E. coli. Various E. coli
strains are publicly available, such as E. coli K12 strain MM294
(ATCC 31,446); E. coli X1776 (ATCC 31,537); E. coli strain W3110
(ATCC 27,325) and K5 772 (ATCC 53,635). In addition to prokaryotes,
eukaryotic microorganisms such as filamentous fungi or yeast are
suitable cloning or expression hosts for vectors encoding MauMan1
polypeptides. Saccharomyces cerevisiae is a commonly used lower
eukaryotic host microorganism.
[0212] In some embodiments, the microorganism to be transformed
includes a strain derived from Trichoderma spp. or Aspergillus spp.
Exemplary strains include T. reesei which is useful for obtaining
overexpressed protein or Aspergillus niger var. awamori. For
example, Trichoderma strain RL-P37, described by Sheir-Neiss et al.
in Appl. Microbiol. Biotechnology, 20 (1984) pp. 46-53 is known to
secrete elevated amounts of cellulase enzymes. Functional
equivalents of RL-P37 include Trichoderma reesei (longibrachiatum)
strain RUT-C30 (ATCC No. 56765) and strain QM9414 (ATCC No. 26921).
Another example includes overproducing mutants as described in Ward
et al. in Appl. Microbiol. Biotechnology 39:738-743 (1993). For
example, it is contemplated that these strains would also be useful
in overexpressing a Mahella australiensis MauMan1 polypeptide, or a
variant thereof. The selection of the appropriate host cell is
deemed to be within the skill in the art.
Preparation and Use of a Replicable Vector
[0213] DNA encoding the MauMan1 protein or derivatives thereof (as
described above) is prepared for insertion into an appropriate
microorganism. According to the present compositions and methods,
DNA encoding a MauMan1 polypeptide includes all of the DNA
necessary to encode for a protein which has functional MauMan1
activity. As such, embodiments of the present compositions and
methods include DNA encoding a MauMan1 polypeptide derived from
Mahella spp., including, Mahella australiensis, such as Mahella
australiensis 50-1 BON.
[0214] The DNA encoding MauMan1 may be prepared by the construction
of an expression vector carrying the DNA encoding MauMan1. The
expression vector carrying the inserted DNA fragment encoding the
MauMan1 may be any vector which is capable of replicating
autonomously in a given host organism or of integrating into the
DNA of the host, typically a plasmid, cosmid, viral particle, or
phage. Various vectors are publicly available. It is also
contemplated that more than one copy of DNA encoding a MauMan1 may
be recombined into the strain to facilitate overexpression.
[0215] In certain embodiments, DNA sequences for expressing MauMan1
include the promoter, gene coding region, and terminator sequence
all originate from the native gene to be expressed. Gene truncation
may be obtained by deleting away undesired DNA sequences (e.g.,
coding for unwanted domains) to leave the domain to be expressed
under control of its native transcriptional and translational
regulatory sequences. A selectable marker can also be present on
the vector allowing the selection for integration into the host of
multiple copies of the MauMan1 gene sequences.
[0216] In other embodiments, the expression vector is preassembled
and contains sequences required for high level transcription and,
in some cases, a selectable marker. It is contemplated that the
coding region for a gene or part thereof can be inserted into this
general purpose expression vector such that it is under the
transcriptional control of the expression cassette's promoter and
terminator sequences. For example, pTEX is such a general purpose
expression vector. Genes or part thereof can be inserted downstream
of the strong cbh1 promoter.
[0217] In the vector, the DNA sequence encoding the MauMan1 of the
present compositions and methods should be operably linked to
transcriptional and translational sequences, e.g., a suitable
promoter sequence and signal sequence in reading frame to the
structural gene. The promoter may be any DNA sequence which shows
transcriptional activity in the host cell and may be derived from
genes encoding proteins either homologous or heterologous to the
host cell. The signal peptide provides for extracellular production
(secretion) of the MauMan1 or derivatives thereof. The DNA encoding
the signal sequence can be that which is naturally associated with
the gene to be expressed. However the signal sequence from any
suitable source, for example an exo-cellobiohydrolases or
endoglucanase from Trichoderma, a xylanase from a bacterial
species, e.g., from Streptomyces coelicolor, etc., are contemplated
in the present compositions and methods.
[0218] The appropriate nucleic acid sequence may be inserted into
the vector by a variety of procedures. In general, DNA is inserted
into an appropriate restriction endonuclease site(s) using
techniques known in the art. Vector components generally include,
but are not limited to, one or more of a signal sequence, an origin
of replication, one or more marker genes, an enhancer element, a
promoter, and a transcription termination sequence. Construction of
suitable vectors containing one or more of these components employs
standard ligation techniques which are known to the skilled
artisan.
[0219] A desired MauMan1 polypeptide may be produced recombinantly
not only directly, but also as a fusion polypeptide with a
heterologous polypeptide, which may be a signal sequence or other
polypeptide having a specific cleavage site at the N-terminus of
the mature protein or polypeptide. In general, the signal sequence
may be a component of the vector or it may be a part of the
MauMan1-encoding DNA that is inserted into the vector. The signal
sequence may be a prokaryotic signal sequence selected, for
example, from the group of the alkaline phosphatase, penicillinase,
1pp, or heat-stable enterotoxin II leaders. For yeast secretion the
signal sequence may be, e.g., the yeast invertase leader, alpha
factor leader (including Saccharomyces and Kluyveromyces
.alpha.-factor leaders, the latter described in U.S. Pat. No.
5,010,182), or acid phosphatase leader, the C. albicans
glucoamylase leader (EP 362,179 published 4 Apr. 1990), or the
signal described in WO 90/13646 published 15 Nov. 1990.
[0220] Both expression and cloning vectors may contain a nucleic
acid sequence that enables the vector to replicate in one or more
selected host cells. Such sequences are well known for a variety of
bacteria, yeast, and viruses. The origin of replication from the
plasmid pBR322 is suitable for most Gram-negative bacteria and the
2.mu. plasmid origin is suitable for yeast.
[0221] Expression and cloning vectors will typically contain a
selection gene, also termed a selectable marker. Typical selection
genes encode proteins that (a) confer resistance to antibiotics or
other toxins, e.g., ampicillin, neomycin, methotrexate, or
tetracycline, (b) complement auxotrophic deficiencies, or (c)
supply critical nutrients not available from complex media, e.g.,
the gene encoding D-alanine racemase for Bacilli. A suitable
selection gene for use in yeast is the trp1 gene present in the
yeast plasmid YRp7 (Stinchcomb et al., Nature, 282:39 (1979);
Kingsman et al., Gene, 7:141 (1979); Tschemper et al., Gene, 10:157
(1980)). The trp1 gene provides a selection marker for a mutant
strain of yeast lacking the ability to grow in tryptophan, for
example, ATCC No. 44076 or PEP4-1 (Jones, Genetics, 85:12 (1977)).
An exemplary selection gene for use in Trichoderma sp is the pyr4
gene.
[0222] Expression and cloning vectors usually contain a promoter
operably linked to the MauMan1-encoding nucleic acid sequence. The
promoter directs mRNA synthesis. Promoters recognized by a variety
of potential host cells are well known. Promoters include a fungal
promoter sequence, for example, the promoter of the cbh1 or egl1
gene.
[0223] Promoters suitable for use with prokaryotic hosts include
the .beta.-lactamase and lactose promoter systems (Chang et al.,
Nature, 275:615 (1978); Goeddel et al., Nature, 281:544 (1979)),
alkaline phosphatase, a tryptophan (trp) promoter system (Goeddel,
Nucleic Acids Res., 8:4057 (1980); EP 36,776), and hybrid promoters
such as the tac promoter (deBoer et al., Proc. Natl. Acad. Sci.
USA, 80:21-25 (1983)). Additional promoters, e.g., the A4 promoter
from A. niger, also find use in bacterial expression systems, e.g.,
in S. lividans. Promoters for use in bacterial systems also may
contain a Shine-Dalgarno (S.D.) sequence operably linked to the DNA
encoding a MauMan1 polypeptide.
[0224] Examples of suitable promoting sequences for use with yeast
hosts include the promoters for 3-phosphoglycerate kinase (Hitzeman
et al., J. Biol. Chem., 255:2073 (1980)) or other glycolytic
enzymes (Hess et al., J. Adv. Enzyme Reg., 7:149 (1968); Holland,
Biochemistry, 17:4900 (1978)), such as enolase,
glyceraldehyde-3-phosphate dehydrogenase, hexokinase, pyruvate
decarboxylase, phosphofructokinase, glucose-6-phosphate isomerase,
3-phosphoglycerate mutase, pyruvate kinase, triosephosphate
isomerase, phosphoglucose isomerase, and glucokinase. Other yeast
promoters, which are inducible promoters having the additional
advantage of transcription controlled by growth conditions, are the
promoter regions for alcohol dehydrogenase 2, isocytochrome C, acid
phosphatase, degradative enzymes associated with nitrogen
metabolism, metallothionein, glyceraldehyde-3-phosphate
dehydrogenase, and enzymes responsible for maltose and galactose
utilization. Suitable vectors and promoters for use in yeast
expression are further described in EP 73,657.
[0225] Expression vectors used in eukaryotic host cells (e.g.
yeast, fungi, insect, plant) will also contain sequences necessary
for the termination of transcription and for stabilizing the mRNA.
Such sequences are commonly available from the 5' and, occasionally
3', untranslated regions of eukaryotic or viral DNAs or cDNAs.
These regions contain nucleotide segments transcribed as
polyadenylated fragments in the untranslated portion of the mRNA
encoding a MauMan1 polypeptide.
Purification of a MauMan1 Polypeptide
[0226] Forms of MauMan1 polypeptides (or MauMan1 polypeptide
derivatives) may be recovered from culture medium or from host cell
lysates by the methods described above for isolation and
purification from natural isolates. Additional techniques can be
used depending on the host cell employed and any variant structures
in the recombinant enzyme. For example, if the recombinant enzyme
is membrane-bound, it can be released from the membrane using a
suitable detergent solution (e.g. Triton-X 100) or by enzymatic
cleavage. Purification of recombinant enzyme may also employ
protein A Sepharose columns to remove contaminants such as IgG and
metal chelating columns to bind epitope-tagged forms of the MauMan1
polypeptide. The purification step(s) selected will depend, for
example, on the nature of the production process used, the
particular MauMan1 polypeptide that is produced, and any variant
structure for the recombinant enzyme. Antibodies directed to a
MauMan1 polypeptide or epitope tags thereon may also be employed to
purify the protein, e.g., anti-MauMan1 antibodies attached to a
solid support.
Derivatives of MauMan1
[0227] As described above, in addition to the native sequence of
MauMan1 described herein (e.g., as depicted in full length as SEQ
ID NO:2, and in the mature form as SEQ ID NO: 3), it is
contemplated that MauMan1 derivatives can be prepared with altered
amino acid sequences. In general, MauMan1 derivatives would be
capable of conferring, as a native MauMan1 polypeptide, to a
cellulase and/or hemicellulase mixture or composition either one or
both of an improved capacity to hydrolyze a lignocellulosic biomass
substrate, in particular one that is mannan-containing, and an
improved capacity to reduce viscosity of a biomass substrate
mixture, particularly one that is at a high solids level. Such
derivatives may be made, for example, to improve expression in a
particular host, improve secretion (e.g., by altering the signal
sequence), to introduce epitope tags or other sequences that can
facilitate the purification and/or isolation of MauMan1
polypeptides. In some embodiments, derivatives may confer more
capacity to hydrolyze a lignocellulosic biomass substrate to a
cellulase and/or hemicellulase mixture or composition, as compared
to the native MauMan1 polypeptide. In some embodiments, derivatives
may confer a higher viscosity reduction benefit (e.g., an
improvement or even higher speed and/or extent of viscosity
reduction) to a cellulase and/or hemicellulase mixture, as compared
to the native MauMan1 polypeptide.
[0228] MauMan1 polypeptide derivatives can be prepared by
introducing appropriate nucleotide changes into the
MauMan1-encoding DNA, or by synthesis of the desired MauMan1
polypeptides. Those skilled in the art will appreciate that amino
acid changes may alter post-translational processes of the MauMan1
polypeptides, such as changing the number or position of
glycosylation sites.
[0229] Derivatives of the native sequence MauMan1 polypeptide or of
various domains of the MauMan1 described herein can be made, for
example, using any of the techniques and guidelines for
conservative and non-conservative mutations set forth, for
instance, in U.S. Pat. No. 5,364,934. Sequence variations may be a
substitution, deletion or insertion of one or more codons encoding
the MauMan1 polypeptide that results in a change in the amino acid
sequence of the MauMan1 polypeptide as compared with the native
sequence MauMan1 polypeptide. Optionally, the sequence variation is
by substitution of at least one amino acid with any other amino
acid in one or more of the domains of the MauMan1 polypeptide.
[0230] Guidance in determining which amino acid residue may be
inserted, substituted or deleted without adversely affecting the
desired MauMan1 beta-mannanase activity may be found by comparing
the sequence of the polypeptide with that of homologous known
protein molecules and minimizing the number of amino acid sequence
changes made in regions of high homology. Amino acid substitutions
can be the result of replacing one amino acid with another amino
acid having similar structural and/or chemical properties, such as
the replacement of a leucine with a serine, i.e., conservative
amino acid replacements. Insertions or deletions may optionally be
in the range of 1 to 5 amino acids. The variation allowed may be
determined by systematically making insertions, deletions or
substitutions of amino acids in the sequence and testing the
resulting derivatives for functional activity using techniques
known in the art.
[0231] The sequence variations can be made using methods known in
the art such as oligonucleotide-mediated (site-directed)
mutagenesis, alanine scanning, and PCR mutagenesis. Site-directed
mutagenesis (Carter et al., Nucl. Acids Res., 13:4331 (1986);
Zoller et al., Nucl. Acids Res., 10:6487 (1987)), cassette
mutagenesis (Wells et al., Gene, 34:315 (1985)), restriction
selection mutagenesis (Wells et al., Philos. Trans. R. Soc. London
SerA, 317:415 (1986)) or other known techniques can be performed on
the cloned DNA to produce the MauMan1-encoding DNA with a variant
sequence.
[0232] Scanning amino acid analysis can also be employed to
identify one or more amino acids along a contiguous sequence. Among
the scanning amino acids the can be employed are relatively small,
neutral amino acids. Such amino acids include alanine, glycine,
serine, and cysteine. Alanine is often used as a scanning amino
acid among this group because it eliminates the side-chain beyond
the beta-carbon and is less likely to alter the main-chain
conformation of the derivative. Alanine is also often used because
it is the most common amino acid. Further, it is frequently found
in both buried and exposed positions (Creighton, The Proteins,
(W.H. Freeman & Co., N.Y.); Chothia, J. Mol. Biol., 150:1
(1976)). If alanine substitution does not yield adequate amounts of
derivative, an isosteric amino acid can be used.
Anti-MauMan1 Antibodies
[0233] The present compositions and methods further provides
anti-MauMan1 antibodies. Exemplary antibodies include polyclonal
and monoclonal antibodies, including chimeric and humanized
antibodies.
[0234] The anti-MauMan1 antibodies of the present compositions and
methods may include polyclonal antibodies. Any convenient method
for generating and preparing polyclonal and/or monoclonal
antibodies may be employed, a number of which are known to those
ordinarily skilled in the art.
[0235] Anti-MauMan1 antibodies may also be generated using
recombinant DNA methods, such as those described in U.S. Pat. No.
4,816,567.
[0236] The antibodies may be monovalent antibodies, which may be
generated by recombinant methods or by the digestion of antibodies
to produce fragments thereof, particularly, Fab fragments.
Cell Culture Media
[0237] Generally, the microorganism is cultivated in a cell culture
medium suitable for production of the MauMan1 polypeptides
described herein. The cultivation takes place in a suitable
nutrient medium comprising carbon and nitrogen sources and
inorganic salts, using procedures and variations known in the art.
Suitable culture media, temperature ranges and other conditions for
growth and cellulase production are known in the art. As a
non-limiting example, a typical temperature range for the
production of cellulases by Trichoderma reesei is 24.degree. C. to
37.degree. C., for example, between 25.degree. C. and 30.degree.
C.
Cell Culture Conditions
[0238] Materials and methods suitable for the maintenance and
growth of fungal cultures are well known in the art. In some
aspects, the cells are cultured in a culture medium under
conditions permitting the expression of one or more beta-mannanase
polypeptides encoded by a nucleic acid inserted into the host
cells. Standard cell culture conditions can be used to culture the
cells. In some aspects, cells are grown and maintained at an
appropriate temperature, gas mixture, and pH. In some aspects,
cells are grown at in an appropriate cell medium.
Compositions Comprising a Recombinant Beta-Mannanase MauMan1
Polypeptide
[0239] The present disclosure provides engineered enzyme
compositions (e.g., cellulase compositions) or fermentation broths
enriched with a recombinant MauMan1 polypeptides. In some aspects,
the composition is a cellulase composition. The cellulase
composition can be, e.g., a filamentous fungal cellulase
composition, such as a Trichoderma cellulase composition. The
cellulase composition can be, in some embodiments, an admixture or
physical mixture, of various cellulases originating from different
microorganisms; or it can be one that is the culture broth of a
single engineered microbe co-expressing the celluase genes; or it
can be one that is the admixture of one or more
individually/separately obtained cellulases with a mixture that is
the culture broth of an engineered microbe co-expressing one or
more cellulase genes.
[0240] In some aspects, the composition is a cell comprising one or
more nucleic acids encoding one or more cellulase polypeptides. In
some aspects, the composition is a fermentation broth comprising
cellulase activity, wherein the broth is capable of converting
greater than about 50% by weight of the cellulose present in a
biomass sample into sugars. The term "fermentation broth" and
"whole broth" as used herein refers to an enzyme preparation
produced by fermentation of an engineered microorganism that
undergoes no or minimal recovery and/or purification subsequent to
fermentation. The fermentation broth can be a fermentation broth of
a filamentous fungus, for example, a Trichoderma, Humicola,
Fusarium, Aspergillus, Neurospora, Penicillium, Cephalosporium,
Achlya, Podospora, Endothia, Mucor, Cochliobolus, Pyricularia,
Myceliophthora or Chrysosporium fermentation broth. In particular,
the fermentation broth can be, for example, one of Trichoderma spp.
such as a Trichoderma reesei, or Penicillium spp., such as a
Penicillium funiculosum. The fermentation broth can also suitably
be a cell-free fermentation broth. In one aspect, any of the
cellulase, cell, or fermentation broth compositions of the present
invention can further comprise one or more hemicellulases.
[0241] In some aspects, the whole broth composition is expressed in
T. reesei or an engineered strain thereof. In some aspects the
whole broth is expressed in an integrated strain of T. reesei
wherein a number of cellulases including a MauMan1 polypeptide has
been integrated into the genome of the T. reesei host cell. In some
aspects, one or more components of the polypeptides expressed in
the integrated T. reesei strain have been deleted.
[0242] In some aspects, the whole broth composition is expressed in
A. niger or an engineered strain thereof.
[0243] Alternatively, the recombinant MauMan1 polypeptides can be
expressed intracellularly. Optionally, after intracellular
expression of the enzyme variants, or secretion into the
periplasmic space using signal sequences such as those mentioned
above, a permeabilisation or lysis step can be used to release the
recombinant MauMan1 polypeptide into the supernatant. The
disruption of the membrane barrier is effected by the use of
mechanical means such as ultrasonic waves, pressure treatment
(French press), cavitation, or by the use of membrane-digesting
enzymes such as lysozyme or enzyme mixtures.
[0244] In some aspects, the polynucleotides encoding the
recombinant MauMan1 polypeptide are expressed using a suitable
cell-free expression system. In cell-free systems, the
polynucleotide of interest is typically transcribed with the
assistance of a promoter, but ligation to form a circular
expression vector is optional. In some embodiments, RNA is
exogenously added or generated without transcription and translated
in cell-free systems.
Uses of MauMan1 Polypeptides to Hydrolyze a Lignocellulosic Biomass
Substrate
[0245] In some aspects, provided herein are methods for converting
lignocelluloses biomass to sugars, the method comprising contacting
the biomass substrate with a composition disclosed herein
comprising a MauMan1 polypeptide in an amount effective to convert
the biomass substrate to fermentable sugars. Suitably the biomass
substrate comprises GGM and/or GM. In certain embodiments, a
suitable biomass substrate may contain up to about 2 wt. % or more,
about 3 wt. % or more, about 4 wt. % or more, about 5 wt. % or
more, etc. of GGM and/or GM.
[0246] In some aspects, the method further comprises pretreating
the biomass with acid and/or base and/or mechanical or other
physical means In some aspects the acid comprises phosphoric acid.
In some aspects, the base comprises sodium hydroxide or ammonia. In
some aspects, the mechanical means may include, for example,
pulling, pressing, crushing, grinding, and other means of
physically breaking down the lignocellulosic biomass into smaller
physical forms. Other physical means may also include, for example,
using steam or other pressurized fume or vapor to "loosen" the
lignocellulosic biomass in order to increase accessibility by the
enzymes to the cellulose and hemicellulose. In certain embodiments,
the method of pretreatment may also involve enzymes that are
capable of breaking down the lignin of the lignocellulosic biomass
substrate, such that the accessibility of the enzymes of the
biomass hydrolyzing enzyme composition to the cellulose and the
hemicelluloses of the biomass is increased.
[0247] Biomass:
[0248] The disclosure provides methods and processes for biomass
saccharification, using the enzyme compositions of the disclosure,
comprising a MauMan1 polypeptide. The term "biomass," as used
herein, refers to any composition comprising cellulose and/or
hemicellulose (optionally also lignin in lignocellulosic biomass
materials). Particularly suitable are lignocellulosic biomass
materials comprising measureable amounts of galactoglucomannans
(GGMs) and/or glucomannan (GMs). Such biomass materials may
include, for example, a KRAFT-alkaline pretreated industrial
unbleached softwood pulp, FPP-27, which can be obtained from Agence
Nationale de la Recherche, France, which contains about 6.5 wt. %
mannan; a SPORL-pretreated softwood (Zhu J. Y. et al., (2010) Appl.
Microbiol. Biotechnol. 86(5):1355-65; Tian S. et al., (2010)
Bioresour. Technol. 101:8678-85), which contains about 4.5 wt. %
mannan; spruce, which may contain over 10 wt. % of mannan. As used
herein, biomass includes, without limitation, certain softwood
trees such as spruce, pine, aspen trees, and wastes derived
therefrom, seeds, grains, tubers, plant waste (such as, for
example, empty fruit bunches of the palm trees, or palm fibre
wastes) or byproducts of food processing or industrial processing
(e.g., stalks), corn (including, e.g., cobs, stover, and the like),
grasses (including, e.g., Indian grass, such as Sorghastrum nutans;
or, switchgrass, e.g., Panicum species, such as Panicum virgatum),
perennial canes (e.g., giant reeds), wood (including, e.g., wood
chips, processing waste), paper, pulp, and recycled paper
(including, e.g., newspaper, printer paper, and the like). Other
biomass materials include, without limitation, potatoes, soybean
(e.g., rapeseed), barley, rye, oats, wheat, beets, and sugar cane
bagasse.
[0249] The disclosure therefore provides methods of
saccharification comprising contacting a composition comprising a
biomass material, for example, a material comprising xylan,
hemicellulose, and in particular, galactoglucomannans (GGMs) and/or
glucomannans (GMs), cellulose, and/or a fermentable sugar, with a
MauMan1 polypeptide of the disclosure, or a MauMan1 polypeptide
encoded by a nucleic acid or polynucleotide of the disclosure, or
any one of non-naturally occurring the cellulase and/or
hemicellulase compositions comprising a MauMan1 polypeptide, or
products of manufacture of the disclosure.
[0250] The saccharified biomass (e.g., lignocellulosic material
processed by enzymes of the disclosure) can be made into a number
of bio-based products, via processes such as, e.g., microbial
fermentation and/or chemical synthesis. As used herein, "microbial
fermentation" refers to a process of growing and harvesting
fermenting microorganisms under suitable conditions. The fermenting
microorganism can be any microorganism suitable for use in a
desired fermentation process for the production of bio-based
products. Suitable fermenting microorganisms include, without
limitation, filamentous fungi, yeast, and bacteria. The
saccharified biomass can, for example, be made it into a fuel
(e.g., a biofuel such as a bioethanol, biobutanol, biomethanol, a
biopropanol, a biodiesel, a jet fuel, or the like) via fermentation
and/or chemical synthesis. The saccharified biomass can, for
example, also be made into a commodity chemical (e.g., ascorbic
acid, isoprene, 1,3-propanediol), lipids, amino acids,
polypeptides, and enzymes, via fermentation and/or chemical
synthesis.
[0251] Pretreatment:
[0252] Prior to saccharification or enzymatic hydrolysis and/or
fermentation of the fermentable sugars resulting from the
saccharification, biomass (e.g., lignocellulosic material) is
preferably subject to one or more pretreatment step(s) in order to
render xylan, hemicellulose, cellulose and/or lignin material more
accessible or susceptible to the enzymes in the enzymatic
composition (for example, the enzymatic composition of the present
invention comprising a MauMan1 polypeptide) and thus more amenable
to hydrolysis by the enzyme(s) and/or the enzyme compositions.
[0253] In some aspects, a suitable pretreatment method may involve
subjecting biomass material to a catalyst comprising a dilute
solution of a strong acid and a metal salt in a reactor. The
biomass material can, e.g., be a raw material or a dried material.
This pretreatment can lower the activation energy, or the
temperature, of cellulose hydrolysis, ultimately allowing higher
yields of fermentable sugars. See, e.g., U.S. Pat. Nos. 6,660,506;
6,423,145.
[0254] In some aspects, a suitable pretreatment method may involve
subjecting the biomass material to a first hydrolysis step in an
aqueous medium at a temperature and a pressure chosen to effectuate
primarily depolymerization of hemicellulose without achieving
significant depolymerization of cellulose into glucose. This step
yields a slurry in which the liquid aqueous phase contains
dissolved monosaccharides resulting from depolymerization of
hemicellulose, and a solid phase containing cellulose and lignin.
The slurry is then subject to a second hydrolysis step under
conditions that allow a major portion of the cellulose to be
depolymerized, yielding a liquid aqueous phase containing
dissolved/soluble depolymerization products of cellulose. See,
e.g., U.S. Pat. No. 5,536,325.
[0255] In further aspects, a suitable pretreatment method may
involve processing a biomass material by one or more stages of
dilute acid hydrolysis using about 0.4% to about 2% of a strong
acid; followed by treating the unreacted solid lignocellulosic
component of the acid hydrolyzed material with alkaline
delignification. See, e.g., U.S. Pat. No. 6,409,841.
[0256] In yet further aspects, a suitable pretreatment method may
involve pre-hydrolyzing biomass (e.g., lignocellulosic materials)
in a pre-hydrolysis reactor; adding an acidic liquid to the solid
lignocellulosic material to make a mixture; heating the mixture to
reaction temperature; maintaining reaction temperature for a period
of time sufficient to fractionate the lignocellulosic material into
a solubilized portion containing at least about 20% of the lignin
from the lignocellulosic material, and a solid fraction containing
cellulose; separating the solubilized portion from the solid
fraction, and removing the solubilized portion while at or near
reaction temperature; and recovering the solubilized portion. The
cellulose in the solid fraction is rendered more amenable to
enzymatic digestion. See, e.g., U.S. Pat. No. 5,705,369. In a
variation of this aspect, the pre-hydrolyzing can alternatively or
further involves pre-hydrolysis using enzymes that are, for
example, capable of breaking down the lignin of the lignocellulosic
biomass material.
[0257] In yet further aspects, suitable pretreatments may involve
the use of hydrogen peroxide H.sub.2O.sub.2. See Gould, 1984,
Biotech, and Bioengr. 26:46-52.
[0258] In further aspects, suitable pretreatment of the
lignocellulosic biomass materials, in particular those comprising
measurable amounts of galactoglucomannans (GGMs) and/or
glucomannans (GMs), may include the KRAFT alkaline pretreatment
method employed by, for example, the Agence Nationale de la
Recherche, France. The KRAFT pretreatment method is a well-known
and widely used method to convert wood into wood pulp, typically
including the treatment of wood chips with a mixture of sodium
hydroxide and sodium sulfide, known in the industry as "white
liquor," which breaks down the bonds that link lignin to the
cellulose. It is a long-practiced method, mostly in the paper and
pulp industry, originally invented by Carl F. Dahl in 1879, as
described in U.S. Pat. No. 296,935, issued in 1884. Also included
are the SPORL pretreatment method developed by the United States
Department of Agriculture specifically for certain softwood biomass
feedstocks, for example, for pine, spruce and aspen tree materials,
such as described in Zhu et al., (2009) Bioresource Technol.
100:2411-18. The SPORL pretreatment method involves using sulfite
to treat wood chips of such softwoods under acidic conditions
followed by mechanical size reduction using disk refining. The
SPORL method was reported to produce a reduced amounts of
fermentation inhibitors such as hydroxyl-methyl furfural and/or
furfural.
[0259] In other aspects, pretreatment can also comprise contacting
a biomass material with stoichiometric amounts of sodium hydroxide
and ammonium hydroxide at a very low concentration. See Teixeira et
al., (1999), Appl. Biochem. and Biotech. 77-79:19-34.
[0260] In some embodiments, pretreatment can comprise contacting a
lignocellulose with a chemical (e.g., a base, such as sodium
carbonate or potassium hydroxide) at a pH of about 9 to about 14 at
moderate temperature, pressure, and pH. See Published International
Application WO2004/081185. Ammonia is used, for example, in a
preferred pretreatment method. Such a pretreatment method comprises
subjecting a biomass material to low ammonia concentration under
conditions of high solids. See, e.g., U.S. Patent Publication No.
20070031918 and Published International Application WO
06110901.
The Saccharification Process
[0261] In some aspects, provided herein is a saccharification
process comprising treating a lignocellulosic biomass material, in
particular, one comprising a measurable amount of
galactoglucomannans (GGMs) and/or glucomannans (GMs), with an
enzyme composition comprising a polypeptide, wherein the
polypeptide has beta-mannanase activity and wherein the process
results in at least about 50 wt. % (e.g., at least about 55 wt. %,
60 wt. %, 65 wt. %, 70 wt. %, 75 wt. %, or 80 wt. %) conversion of
the biomass to fermentable sugars. In some aspects, the biomass
comprises lignin. In some aspects the biomass comprises cellulose.
In some aspects the biomass comprises hemicelluloses. In some
aspects, the biomass comprising cellulose further comprises one or
more of mannan, xylan, galactan, and/or arabinan. In certain
particular aspects, the biomass comprising cellulose as well as at
least a measurable level of galactoglucomannan and/or glucomannan.
In some aspects, the biomass may be, without limitation, softwood
plants (e.g., pine, spruce, aspen trees), seeds, grains, tubers,
plant waste (e.g., empty fruit bunch from palm trees, or palm fibre
waste) or byproducts of food processing or industrial processing
(e.g., stalks), corn (including, e.g., cobs, stover, and the like),
grasses (including, e.g., Indian grass, such as Sorghastrum nutans;
or, switchgrass, e.g., Panicum species, such as Panicum virgatum),
perennial canes (e.g., giant reeds), woody materials (including,
e.g., wood chips, processing waste), paper, pulp, and recycled
paper (including, e.g., newspaper, printer paper, and the like),
potatoes, soybean (e.g., rapeseed), barley, rye, oats, wheat,
beets, and sugar cane bagasse.
[0262] In some aspects, the material comprising biomass is subject
to one or more pretreatment methods/steps prior to treatment with
the MauMan1 polypeptide or the composition comprising the MauMan1
polypeptide. In some aspects, the saccharification or enzymatic
hydrolysis further comprises treating the biomass with an enzyme
composition comprising a MauMan1 polypeptide of the invention. The
enzyme composition may, for example, comprise one or more
cellulases, for example, one or more endoglucanases, one or more
cellobiohydrolases, and/or one or more beta-glucosidases, in
addition to the MauMan1 polypeptide. Alternatively, the enzyme
composition may comprise one or more other hemicellulases, for
example, one or more other beta-mannanases, one or more xylanases,
one or more beta-xylosidases, and/or one or more
L-arabinofuranosidases. In certain embodiments, the enzyme
composition comprises a MauMan1 polypeptide of the invention, one
or more cellulases, one or more other hemicellulases. In some
embodiments, the enzyme composition is a fermentation broth
composition, optionally subject to some
post-production/fermentation processing. In certain embodiments,
the enzyme composition is a whole broth formulation.
[0263] In some aspects, provided is a saccharification process
comprising treating a lignocellulosic biomass material with a
composition comprising a polypeptide, wherein the polypeptide has
at least about 55% (e.g., at least about 55%, 60%, 65%, 70%, 75%,
80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%)
sequence identity to SEQ ID NO:2, or to the mature sequence of SEQ
ID NO:3, and wherein the process results in at least about 50%
(e.g., at least about 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90%) by
weight conversion of biomass to fermentable sugars. In some
aspects, lignocellulosic biomass material has been subject to one
or more pretreatment methods/steps as described herein.
[0264] Other aspects and embodiments of the present compositions
and methods will be apparent from the foregoing description and
following examples.
EXAMPLES
[0265] The following examples are put forth so as to provide those
of ordinary skill in the art with a complete disclosure and
description of how to make and use the present compositions and
methods, and are not intended to limit the scope of what the
inventors regard as their inventive compositions and methods nor
are they intended to represent that the experiments below are all
or the only experiments performed. Efforts have been made to ensure
accuracy with respect to numbers used (e.g. amounts, temperature,
etc.) but some experimental errors and deviations should be
accounted for.
Example 1
Cloning of Mahella australiensis Glycosyl Hydrolase MauMan1
[0266] Mahella australiensis was selected as a potential source for
various glycosyl hydrolases and other enzymes, useful for
industrial applications. Genomic DNA for sequencing was obtained by
first growing a strain of Mahella australiensis, 50-1 BON on LB
agar plates at 30.degree. C. for about 24 hours. Cell material was
scraped from the plates and used to prepare genomic DNA using
phenol/chloroform extraction. The genomic DNA was used for
sequencing, as well as for amplifying the MauMan1 gene for
subsequent expression cloning.
[0267] The MauMan1 gene was identified from the genomic sequence.
The nucleic acid sequence of this gene comprises the polynucleotide
sequence of SEQ ID NO:1, with the nucleic acid residues encoding
the predicted native signal peptide in italics:
TABLE-US-00007 AATGAAACT
AAAGCGGCTCCTTCGATCGCATCTACAGGTATAGATGTGAGCAGTTTA
AAAGGGGTTAATCATGCACATACCTGGTATCCAGATAGGCTGGTTCAA
GCTCTGCAAGGCATTCAGTCATGGGGAGCCAATTCTGTGAGAGTTGTC
TTAAGTAATGGATGCAAGTGGGCAAAAAATAGTGCTAGTGATGTAGCA
AATGTGATATCTAAAGCTCAACAGCTCGGTTTTACAGCAGTTATATTG
GAAGTGCACGATACTACAGGATATGGAGAAGACAGCTCAGCTTGTTCG
CTTAATGATGCCGTAGCCTATTGGAAAGAAATTCAGAGCGTTCTTATA
GGTAAAGAAGACTTCGTTATAATAAATATAGGTAATGAACCATATGGA
AATAATAATTATCAAAACTGGACACAGGATACTATTGATGCTATCAAT
GCGTTAAGAGAAGCAGGATTTAATCATACTATCATGGTAGATGCACCG
AACTGGGGACAGGATTGGTCATTTACAATGAGGGATAATGCTCCAAAG
GTATATGCAGCGGATCCGAATAAAAACATGGTGTTTTCTATCCACATG
TATGGGGTTTATAACACGGCTCAAAAAGTGCATGATTATTTCCAAGCA
TTCAAAGATATGAATTTACCTCTGGTAGTTGGTGAATTTGGAAACCAG
CATTCCGACGGAGATCCTGATGAAGAAGCTATAGTGAGCTATGCAAAA
CAGTATGGTATTGGATACCTTGGTTGGTCATGGTGCGGTAATAGCGGT
GGTGTGGAGTATCTCGATATGGTAAATAATTGGGATGCGAACAGCCCT
ACTTCTTGGGGAAACTGGTTTAAAACCAATGCTCTTGCAGAAATTACG
CCGCCGTCGGACACCACACCACCTGCAGCACCTACAGGATTGACGGCC
ACAGCCGTAAGTTCGAGCAGCATAAACCTCGATTGGGCTGATAATACG
GACAGCGACCTGGCCGGATATAAAGTATACAGAAGCACGTTCAGCGGT
TTCACACCTAGTAGCGCCAACTTCGCGAAGCAGGTAACAAGCAGCGCT
TACACCGATACGGGCTTGACTGCCGATACAACGTATTACTATAAGGTG
ACGGCAGTAGATACCAGCGGCAATGAATCACAACCATCGGCACAGGCC
AGCGCTAAAACACAACAAGGTGGAGGTACAACACCGCCGGGAGAATAT
ACTGAGATTACTTTACCGTTTACCCACGACGGAGCAGGGGAATATTAC
TGGAAGACAAATAAACTTTCCACTGATCCCAATGACTGGAGCCACTAT
ATAAACTCGTGGAATCTCGATCTTCTTGAGATCAACGGAAAAAACTAC
ACCAATGTATGGGTGGCACAACACCAGATAGCACCTTTGTCAGACGGT
TACTGGTATATTCACTGCAAAGGGGGTTTCTCATACTCTCATGTAGAG ATTAAGTAA
[0268] The amino acid sequence of the MauMan1 precursor protein is
provided below as SEQ ID NO:2, with the predicted native signal
peptide presented in italic and bold letters:
TABLE-US-00008 NETKAAPSIASTGIDVSSLK
GVNHAHTWYPDRLVQALQGIQSWGANSVRVVLSNGCKWAKNSASDVANV
ISKAQQLGFTAVILEVHDTTGYGEDSSACSLNDAVAYWKEIQSVLIGKE
DFVIINIGNEPYGNNNYQNWTQDTIDAINALREAGFNHTIMVDAPNWGQ
DWSFTMRDNAPKVYAADPNKNMVFSIHMYGVYNTAQKVHDYFQAFKDMN
LPLVVGEFGNQHSDGDPDEEAIVSYAKQYGIGYLGWSWCGNSGGVEYLD
MVNNWDANSPTSWGNWFKTNALAEITPPSDTTPPAAPTGLTATAVSSSS
INLDWADNTDSDLAGYKVYRSTFSGFTPSSANFAKQVTSSAYTDTGLTA
DTTYYYKVTAVDTSGNESQPSAQASAKTQQGGGTTPPGEYTEITLPFTH
DGAGEYYWKTNKLSTDPNDWSHYINSWNLDLLEINGKNYTNVWVAQHQI
APLSDGYWYIHCKGGFSYSHVEIK
[0269] The amino acid sequence of the mature MauMan1 protein is
provided below as SEQ ID NO:3:
TABLE-US-00009 NETKAAPSIASTGIDVSSLKGVNHAHTWYPDRLVQALQGIQSWGANSVR
VVLSNGCKWAKNSASDVANVISKAQQLGFTAVILEVHDTTGYGEDSSAC
SLNDAVAYWKEIQSVLIGKEDFVIINIGNEPYGNNNYQNWTQDTIDAIN
ALREAGFNHTIMVDAPNWGQDWSFTMRDNAPKVYAADPNKNMVFSIHMY
GVYNTAQKVHDYFQAFKDMNLPLVVGEFGNQHSDGDPDEEAIVSYAKQY
GIGYLGWSWCGNSGGVEYLDMVNNWDANSPTSWGNWFKTNALAEITPPS
DTTPPAAPTGLTATAVSSSSINLDWADNTDSDLAGYKVYRSTFSGFTPS
SANFAKQVTSSAYTDTGLTADTTYYYKVTAVDTSGNESQPSAQASAKTQ
QGGGTTPPGEYTEITLPFTHDGAGEYYWKTNKLSTDPNDWSHYINSWNL
DLLEINGKNYTNVWVAQHQIAPLSDGYWYIHCKGGFSYSHVEIK
[0270] The polypeptide was predicted to have a signal peptide of 27
amino acid residues in length, using the Signal P 3.0 program
(www.cbs.dtu/services/SignalP) set to SignalP-NN system
(Emanuelsson et al., Nature Protocols, 2: 953-971, 2007). The
presence of a signal sequence suggests that the MauMan1 polypeptide
is a secreted glycosyl hydrolase.
Example 2
Expression of Mahella australiensis Beta-Mannanase MauMan1 in a
Bacillus subtilis Host
[0271] The DNA sequence encoding mature MauMan1 was synthesized
(Generay, Shanghai, P.R. China) with an alternative start codon
(GTG) and inserted into a Bacillus subtilis expression vector
p2JM103BBI (FIG. 1) (Vogtentanz, Protein Expr. Purif., 55:40-52,
2007). The resulting plasmid was named p2JM-aprE-MauMan1 (FIG. 2).
The plasmid contains an aprE promoter, an aprE signal sequence used
to direct target protein secretion in B. subtilis, an
oligonucleotide encoding peptide Ala-Gly-Lys to facilitate the
secretion of the target enzyme MauMan1, and the synthetic
nucleotide sequence encoding the mature MauMan1 (SEQ ID NO:3).
[0272] The p2JM-aprE-MauMan1 plasmid (FIG. 2) was then introduced
into B. subtilis cells (degUHy32, .DELTA.nprB, .DELTA.vpr,
.DELTA.epr, .DELTA.scoC, .DELTA.wprA, .DELTA.mpr, .DELTA.ispA,
.DELTA.bpr) and the thus derived cells were spread on Luria Agar
plates supplemented with 5 ppm Chloraphenicol. Colonies were picked
and subjected to fermentation in a 250 mL shake flas with an MBD
medium (which is a MOPS-based defined medium, supplemented with
additional 5 mM CaCl.sub.2).
[0273] Following the natural signal peptidase cleavage in the host,
the recombinant MauMan1 polypeptide produced in this manner was
predicted to have and had 3 additional amino acids, Ala-Gly-Lys, at
its amino-terminus.
[0274] The sequence of the MauMan1 gene was confirmed by DNA
sequencing (SEQ ID NO: 6). The gene has an alternative start codon
(GTG). The oligonucleotide encoding the three residue addition
(AGK) is shown by bold and underline:
TABLE-US-00010 GTGAGAAGCAAAAAATTGTGGATCAGCTTGTTGTTTGCGTTAACGTTAA
TCTTTACGATGGCGTTCAGCAACATGAGCGCGCAGGCTGCTGGAAAAAA
CGAAACAAAAGCAGCACCGTCAATTGCATCAACAGGCATTGATGTTTCA
TCACTGAAAGGCGTTAATCATGCGCATACATGGTATCCGGATCGCCTGG
TTCAAGCACTGCAAGGCATTCAAAGCTGGGGAGCAAATTCAGTTAGAGT
TGTTCTGTCAAATGGCTGCAAATGGGCAAAAAATTCAGCATCAGATGTC
GCGAATGTTATTAGCAAAGCACAACAACTGGGCTTTACAGCAGTTATTC
TGGAAGTTCATGATACAACAGGCTATGGCGAAGATTCATCAGCATGCTC
ACTGAATGATGCAGTTGCATATTGGAAAGAAATTCAGTCAGTCCTGATC
GGCAAAGAAGATTTTGTCATTATTAACATCGGCAACGAACCGTATGGCA
ACAATAACTATCAAAACTGGACACAGGATACGATCGATGCAATTAATGC
ACTGAGAGAAGCAGGCTTTAACCATACAATTATGGTTGATGCACCGAAT
TGGGGACAAGATTGGTCATTTACAATGAGAGATAATGCTCCGAAAGTCT
ATGCAGCAGATCCGAATAAAAACATGGTCTTTAGCATCCATATGTATGG
CGTCTATAATACAGCGCAGAAAGTCCATGATTACTTTCAGGCGTTTAAA
GATATGAATCTGCCGCTGGTTGTTGGCGAATTTGGCAATCAACATTCAG
ATGGCGATCCTGATGAAGAGGCAATTGTTTCATATGCGAAACAATATGG
CATTGGCTATCTGGGCTGGTCATGGTGCGGCAATTCAGGCGGAGTTGAA
TATCTGGATATGGTCAATAATTGGGATGCAAATAGCCCGACATCATGGG
GCAATTGGTTTAAAACAAATGCACTGGCAGAAATTACACCGCCTAGCGA
TACAACACCGCCTGCAGCACCGACAGGCCTGACAGCAACAGCAGTTTCA
TCATCATCAATTAATCTGGATTGGGCAGATAACACAGATTCAGATCTGG
CAGGCTATAAAGTCTATAGATCAACATTTTCAGGCTTTACACCGAGCAG
CGCAAATTTTGCTAAACAAGTTACAAGCAGCGCGTATACAGATACAGGA
CTTACAGCAGATACGACGTATTATTACAAAGTTACAGCGGTTGATACGA
GCGGCAATGAATCACAACCGTCAGCACAAGCATCAGCAAAAACACAACA
AGGCGGAGGCACAACACCTCCGGGTGAATATACAGAAATCACACTGCCG
TTTACACATGATGGCGCAGGCGAATACTATTGGAAAACAAATAAACTGA
GCACGGATCCGAATGATTGGAGCCATTATATCAATAGCTGGAACCTGGA
TCTGCTTGAAATTAACGGCAAAAACTATACAAATGTCTGGGTCGCGCAA
CATCAAATTGCACCGCTGTCAGATGGCTATTGGTATATTCATTGCAAAG
GCGGATTTAGCTATAGCCACGTCGAAATCAAA
[0275] The amino acid sequence of the full-length MauMan1
polypeptide expressed from the plasmid p2JM-aprE-MauMan1 was
confirmed and set forth as SEQ ID NO:7, with the signal sequence
shown in italics and the three residue addition shown by bold and
underline.
TABLE-US-00011 MRSKKLWISLLFALTLIFTMAFSNMSAQAAGKNETKAAPSIASTGIDV
SSLKGVNHAHTWYPDRLVQALQGIQSWGANSVRVVLSNGCKWAKNSAS
DVANVISKAQQLGFTAVILEVHDTTGYGEDSSACSLNDAVAYWKEIQS
VLIGKEDFVIINIGNEPYGNNNYQNWTQDTIDAINALREAGFNHTIMV
DAPNWGQDWSFTMRDNAPKVYAADPNKNMVFSIHMYGVYNTAQKVHDY
FQAFKDMNLPLVVGEFGNQHSDGDPDEEAIVSYAKQYGIGYLGWSWCG
NSGGVEYLDMVNNWDANSPTSWGNWFKTNALAEITPPSDTTPPAAPTG
LTATAVSSSSINLDWADNTDSDLAGYKVYRSTFSGFTPSSANFAKQVT
SSAYTDTGLTADTTYYYKVTAVDTSGNESQPSAQASAKTQQGGGTTPP
GEYTEITLPFTHDGAGEYYWKTNKLSTDPNDWSHYINSWNLDLLEING
KNYTNVWVAQHQIAPLSDGYWYIHCKGGFSYSHVEIK
[0276] The amino acid sequence of the MauMan1 mature polypeptide
expressed from the plasmid p2JM-aprE-MauMan1 was confirmed and set
forth as SEQ ID NO:8, with the three residues amino terminal
extension based on the predicted cleavage site shown by bold and
underline.
TABLE-US-00012 AGKNETKAAPSIASTGIDVSSLKGVNHAHTWYPDRLVQALQGIQSWGAN
SVRVVLSNGCKWAKNSASDVANVISKAQQLGFTAVILEVHDTTGYGEDS
SACSLNDAVAYWKEIQSVLIGKEDFVIINIGNEPYGNNNYQNWTQDTID
AINALREAGFNHTIMVDAPNWGQDWSFTMRDNAPKVYAADPNKNMVFSI
HMYGVYNTAQKVHDYFQAFKDMNLPLVVGEFGNQHSDGDPDEEAIVSYA
KQYGIGYLGWSWCGNSGGVEYLDMVNNWDANSPTSWGNWFKTNALAEIT
PPSDTTPPAAPTGLTATAVSSSSINLDWADNTDSDLAGYKVYRSTFSGF
TPSSANFAKQVTSSAYTDTGLTADTTYYYKVTAVDTSGNESQPSAQASA
KTQQGGGTTPPGEYTEITLPFTHDGAGEYYWKTNKLSTDPNDWSHYINS
WNLDLLEINGKNYTNVWVAQHQIAPLSDGYWYIHCKGGFSYSHVEIK
[0277] After the three terminal extension residues were cleaved,
the mature MauMan1 polypeptide was confirmed to have the sequence
of SEQ ID NO:3:
TABLE-US-00013 NETKAAPSIASTGIDVSSLKGVNHAHTWYPDRLVQALQGIQSWGANSVR
VVLSNGCKWAKNSASDVANVISKAQQLGFTAVILEVHDTTGYGEDSSAC
SLNDAVAYWKEIQSVLIGKEDFVIINIGNEPYGNNNYQNWTQDTIDAIN
ALREAGFNHTIMVDAPNWGQDWSFTMRDNAPKVYAADPNKNMVFSIHMY
GVYNTAQKVHDYFQAFKDMNLPLVVGEFGNQHSDGDPDEEAIVSYAKQY
GIGYLGWSWCGNSGGVEYLDMVNNWDANSPTSWGNWFKTNALAEITPPS
DTTPPAAPTGLTATAVSSSSINLDWADNTDSDLAGYKVYRSTFSGFTPS
SANFAKQVTSSAYTDTGLTADTTYYYKVTAVDTSGNESQPSAQASAKTQ
QGGGTTPPGEYTEITLPFTHDGAGEYYWKTNKLSTDPNDWSHYINSWNL
DLLEINGKNYTNVWVAQHQIAPLSDGYWYIHCKGGFSYSHVEIK
[0278] The MauMan1 polypeptide produced in the Bacillus subtilis
host cells, as described above, was secreted into the extracellular
culture medium after expression was complete. Accordingly the
expression culture medium was filtered and concentrated, and used
for protein purification.
Example 3
Purification of Beta-Mannanase MauMan1 from a Culture Medium of
Bacillus subtilis
[0279] A three-step purification procedure was applied, including
an anion exchange, hydrophobic interaction chromatography, and gel
filtration. More specifically, about 700 mL crude broth was taken
from a shake flask fermentor, concentrated using VIVAfLOW 200
(cutoff 10 kD) and buffer exchanged into 20 mM Tris-HCl, pH 7.5.
The broth was then loaded onto a 50-mL Q-Sepharose High Performance
column which had been pre-equilibrated with 20 mM Tris-HCl, pH 7.5
(buffer A). An elution step was then carried out using a linear
gradient from 0 to 50% buffer B, which was 20 mM HCl, pH 7.5 with 1
M NaCl, using a total of 3 column volumes, followed with another 3
column volumes of 100% buffer B. The protein of interest, MauMan1,
was detected in the flow-through fraction.
[0280] A 3 M ammonium sulfate solution was added to the
flow-through fraction to an ultimate concentration of 1 M ammonium
sulfate. The thus pretreated fraction was loaded onto a 50-mL
Phenyl-Sepharose Fast Flow column equilibrated with 20 mM Tris-HCl,
pH 7.5, 1 M ammonium sulfate. A gradient elution was applied, using
3 column volumes of 0-100% buffer A, followed by 3 column volume of
100% buffer A. Relatively pure fractions were selected based on
SDS-PAGE. The fractions containing relatively pure enzymes were
pooled.
[0281] The collected/pooled fractions were concentrated into 10 mL
total volume. Then it was loaded onto the HiLoad.TM. 26/60,
Superdex-75 column (1 column volume=320 mL), which had been
preequilibrated with 20 mM sodium phosphate buffer, pH 7.0, 0.15 M
NaCl. The purities of the fractions were again analyzed using
SDS-PAGE.
[0282] Results indicated that MauMan1 was at least 95% if not
completely purified.
[0283] The pure fractions were pooled and concentrated using an
Amicon Ultra-15 device with 10K molecular weight cutoff. The
purified sample was stored at -80.degree. C. in 20 mM sodium
phosphate buffer (pH 7.0) containing 40% glycerol. Prior to
conducting the biochemical analyses below, the frozen purified
sample was carefully thawed.
Example 4 (Prophetic)
[0284] Expression of Mahella australiensis Beta-Mannanase MauMan1
in a T. reesei Host
[0285] The MauMan1 gene can be amplified from Mahella australiensis
genomic DNA using PCR, with the native signal sequence and a CACC
sequence added to the 5' end of the forward primer for directional
Gateway cloning (Invitrogen, Carlsbad, Calif.). Alternatively, a T.
reesei cbhI signal sequence might be employed, substituting for the
native signal sequence. The PCR product of the MauMan1 gene can be
purified using a Qiaquick PCR Purification Kit (Qiagen). The
purified PCR product can then be cloned into the pENTR/D-TOPO
vector, transformed into One Shot.RTM. TOP10 Chemically Competent
E. coli cells (Invitrogen), and then plated onto LA plates
containing 50 ppm kanamycin. Plasmid DNA can then be obtained from
the E. coli transformants, using a QIAspin plasmid preparation kit
(Qiagen).
[0286] The nucleotide sequence of the inserted DNA can then be
confirmed as SEQ ID NO:1 using well-known sequencing methods. The
pENTR/D-TOPO MauMan1 vector including the confirmed MauMan1 gene
sequence can then be recombined with the expression vector pTrex3gM
(see, e.g., International Published Patent Application WO
05/001036, FIG. 2), using an LR Clonase.RTM. reaction (see,
protocols by Invitrogen).
[0287] The product of the LR Clonase.RTM. reaction (i.e., the
vector pTrex3gM MauMan1) can then be transformed into E. coli One
Shot.RTM. TOP10 Chemically Competent cells (Invitrogen) and plated
on LA medium containing 50 ppm carbenicillin. The pTrex3gM vector
also contains the Aspergillus tubingensis amdS gene, encoding
acetamidase, as a selectable marker for transformation of T.
reesei. The pTrex3gM vector further contains a cbhI promoter and
terminator, which flank the MauMan1 sequence.
[0288] Thereafter, about 0.5 to 1 .mu.g of the expression vector
pTrex3gM MauMan1 (or a fragment amplified by PCR) can be used to
transform a T. reesei strain with its major cellulase genes
deleted, for example, a six-fold deletion strain as described in,
e.g., in International Patent Application Publication No. WO
2010/141779), using the PEG-protoplast method with modifications as
described herein.
[0289] For protoplast preparation, spores can be grown for 16-24
hours at 24.degree. C. in a Trichoderma Minimal Medium MM,
containing 20 g/L glucose, 15 g/L KH.sub.2PO.sub.4, pH 4.5, 5 g/L
(NH.sub.4).sub.2SO.sub.4, 0.6 g/L MgSO.sub.4.times.7H.sub.2O, 0.6
g/L CaCl.sub.2.times.2H.sub.2O, 1 mL of 1000.times. T. reesei Trace
elements solution (5 g/L FeSO.sub.4.times.7H.sub.2O, 1.4 g/L
ZnSO.sub.4.times.7H.sub.2O, 1.6 g/L MnSO.sub.4.times.H.sub.2O, 3.7
g/L CoCl.sub.2.times.6H.sub.2O) with shaking at 150 rpm.
Germinating spores can then be harvested by centrifugation and
treated with 50 mg/mL of Glucanex G200 (Novozymes AG) solution to
lyse the fungal cell walls. Further preparation of the protoplasts
can be performed in accordance with a method described by Penttila
et al. Gene 61(1987)155-164. The transformation mixture, containing
about 1 .mu.g of DNA and at least 1.times.10.sup.7 protoplasts in a
total volume of 200 .mu.L, can then be treated with 2 mL of 25% PEG
solution, diluted with 2 volumes of 1.2 M sorbitol/10 mM Tris,
pH7.5, 10 mM CaCl.sub.2, mixed with 3% selective top agarose MM
containing 20 mM acetamide. The resulting mixture is then poured
onto 2% selective agarose plate containing acetamide. Followed by
that, plates are incubated for 7-10 d at 28.degree. C. Single
transformants are then transferred onto fresh MM plates containing
acetamide. Spores from independent clones are then used to
inoculate a fermentation medium in either 96-well microtiter plates
or shake flasks.
[0290] Secreted protein from the culture broths can be purified,
optionally subject to some post-fermentation processing, or can be
used directly for saccharification or hydrolyzing mannan-containing
lignocellulosic biomass substrates
Example 5
Beta-Mannanase Activity of MauMan1
[0291] The beta-1,4 mannanase activity of MauMan1 was measured
using 0.5% locust bean gum galactomannan from Ceratonia siliqua
seeds (Sigma, G0753), and konjac glucomannan (Megazyme P-GLCML)
(Bray, Ireland) as substrates.
[0292] The assay was performed in a 50 mM sodium acetate buffer, pH
5.0, containing 0.005% Tween-80, whereby the polypeptide and the
substrate were incubated at 50.degree. C. for 10 minutes.
[0293] The reducing sugar(s) released from the hydrolysis reaction
was quantified using a PAHBAH (p-Hydroxy benzoic acid hydrazide)
assay as described by Lever (1972) Anal. Biochem. 47:248. A
standard curve was prepared using various amounts of mannose as
standards, and the specific enzyme activity units were calculated.
Specifically one mannanase unit was defined as the amount of enzyme
required to generate 1 micromole of mannose reducing sugar
equivalents per minute under a given set of conditions.
[0294] As measured, the specific activity of the purified MauMan1
polypeptide was measured to be about 129 units/mg against the
Locust bean gum substrate, and 96 units/mg against the Konjac
glucomannan substrate, at pH 5.0; and about 182 units/mg against
the Locust bean gum substrate, and about 84 units/mg against the
Konjac glucomannana at pH 8.2.
Example 6
pH Profile of MauMan1
[0295] The pH profile of MauMan1 was determined using locust bean
gum from Ceratonia siliqua seeds (Sigma G0753) as substrate. The
enzyme was first diluted in 0.005% Tween-80 to an appropriate
concentration based on the dose response curve. The substrate
solutions buffered using sodium citrate/sodium phosphate buffers of
different pHs were pre-incubated in a thermomixer at 50.degree. C.
for 5 minutes.
[0296] The activity assays were performed in a sodium
citrate/sodium phosphate buffer, having various pH values in a
range between pH 2 and pH 9. Assay reactions were initiated by
addition of enzymes to the substrate mixture. The mixtures were
then incubated at 50.degree. C. for 10 minutes, followed by
termination of reactions by transferring 10 .mu.L reaction mixture
to a 96-well PCR plate, which were preloaded in each well 100 .mu.L
of PAHBAH solutions.
[0297] The PCR plate was then incubated at 95.degree. C. for 5
minutes in a Bio-Rad DNA Engine. Then 100 .mu.L of a mixture in
each well was transferred to a new 96-well assay plate.
[0298] The amount of reducing sugar(s) released from the substrate
was determined by measuring the optical density of the reaction
mixture following the completion of the reaction as described above
at 410 nm in a spectrophotometer. The enzyme activity at each pH
was reported as relative activity where the activity at the pH
optimum was normalized to 100%.
[0299] The pH profile of MauMan1 is shown in FIG. 3. MauMan1 was
found to have an optimum pH at about pH 6.0. The polypeptide was
also found to retain greater than 70% of its maximum activity
between pH 4.0 and pH 9.0.
Example 7
Temperature Profile of MauMan1
[0300] The temperature optimum of purified MauMan1 polypeptide was
determined by measuring the beta-mannanase of MauMan1, at various
temperatures between 40.degree. C. and 90.degree. C., in a 50 mM
sodium citrate buffer, pH 6.0, for 10 minutes for activity upon the
locust bean gum substrate. The activity was reported as relative
activity where the activity at the temperature optimum was
normalized to 100%. The temperature profile of MauMan1 is shown in
FIG. 4.
[0301] MauMan1 was found to have an optimum temperature of about
82.degree. C. MauMan1 was also found to retain greater than 70% of
its maximum activity between the temperatures of 70.degree. C. and
92.degree. C.
Example 8
Thermostability Profile of MauMan1
[0302] The thermostability of MauMan1 was determined in a 50 mM
sodium citrate buffer, pH 6.0. The enzyme was incubated in a PCR
thermal cycler at the desired temperature for 2 hours. The
remaining or residual activity of each sample was measured as
described in Example 5 above. The activity of a control MauMan1
sample kept on ice was used to define a 100%-retained activity. The
thermostability profile of MauMan1 is shown in FIG. 5.
[0303] MauMan1 retained about 50% activity over a 2-hour incubation
period at 72.degree. C. No activity loss was detected after a
2-hour incubation period at temperatures lower than 55.degree. C.,
indicating that MauMan1 was remarkably thermostable.
Example 9
Hydrolysis and Viscosity Benefits of MauMan1 as Observed Over
FPP-27
[0304] An alkaline KRAFT-pretreated softwood substrate FPP-27 was
obtained from Agence Nationale de la Recherche, France
(ARN-05-BIOE-007) through a research project funded by L'Agence
Nationale de I'Environmental et de la Maitrise de I'Energie (ADEME
0501 C0099), and a composition analysis was conducted, indicating
the following content of the biomass: .about.2.5 wt. % Klason
lignin; .about.81.4 wt. % glycan; .about.7.9 wt. % xylan,
.about.0.8 wt. % galactan; and .about.6.5 wt. % mannan.
[0305] The substrate, in an amount of 1.93 g, at a dry solids
loading level of 8.6% and total cellulose loading of 7% was mixed
with an Accellerase.RTM. TRIO.TM. sample (which was pre-diluted
into the desired concentration, as needed, using 0.05 M sodium
citrate buffer, pH 5.0) at 10 mg/g glucan into a reaction mixture
as a control. The substrate, in an amount of 1.93 g, at the same
dry solids loading level of 8.6% and total cellulose loading of 7%,
was mixed with a blended enzyme having 9 mg/g glucan of
Accellerase.RTM. TRIO.TM. and 1 mg/g glucan of MauMan1, or 1 mg/g
glucan of TceMan1, or 1 mg/g ChyMan1 in a reaction mixture. The
reaction mixtures and the control mixture were adjusted to pH 5
using a 0.1 M sodium citrate buffer. A 5% sodium azide was added to
each of the reaction mixtures and control mixture to control
microbial growth.
[0306] The reaction mixture and the control mixture are then
incubated in a New Brunswick Scientific Innova 44 Incubator Shaker
at 50.degree. C., with gentle agitation at 200 rpm. After 24 hours,
48 hours, 72 hours, a small sample of about 100 .mu.L was taken
from each of the reaction mixture, diluted in 0.9 mL of MilliQ
water, followed by filtration through a 0.2 .mu.m filter. The
filtrate was then injected into an Agilent Technologies HPLC,
equipped with an Agilent Technologies 1260 Infinity Separation
Module, set at a flow rate of 0.6 mL/min, and a mobile phase of
MilliQ water degassed with 0.2 .mu.m filter; a Biorad HPX-87P
300.times.7.8 mm column, a Phenomenex Security Guard Kit, including
a Carbo-Ca 4.times.3.0 mm security guard cartridge, and an Agilent
Technologies 1260 Infinity ELSD Dector, set at a nebulizer and
evaporator operating temperature of 45.degree. C., and gas flow
rate of nitrogen at 1.6 SLM. The reaction mixtures as well as the
control sample were analyzed for the amount of glucose, xylose,
arabinose, and mannose. The results are presented in FIGS.
6A-6C.
[0307] As conducted above, the incubation took place with gentle
agitation at a temperature of about 50.degree. C., for at least 72
hours. After at least 72 hours of incubation, the viscosity of each
of the resulting mixtures (about 1.2-1.75 grams of sample) was
determined using the HR-1 rheometer (TA Instruments). A stainless
steel 40-mm parallel plate geometry was used. Viscosity evaluation
was performed at 23.degree. C. using a sweep shear rate from 50
second.sup.-1 to 1 second.sup.-1. The MauMan1 .beta.-mannanase
polypeptide, when mixed with Accellerase.RTM. TRIO.TM. in the
above-described proportions, imparted a substantial and clear
viscosity reduction benefit, achieving at least a 79% reduced
viscosity at the 72-hour incubation point, as compared to the
control samples. The viscosity benefits are presented in a
comparison plot of FIG. 7.
Example 10 (Prophetic)
[0308] Hydrolysis and Viscosity Benefits of MauMan1 as Observed
Over SPORL-Pretreated Softwood Substrate & Acid-Pretreated
Whole Hydrolysate Corn Stover (whPCS)
[0309] A SPORL-preatreated softwood substrate, which has been
determined by a composition analysis to contain the following:
.about.32.4 wt. % klason lignin; .about.49.4 wt. % glucan;
.about.3.4 wt. % xylan; and .about.4.6 wt. % mannan can be used to
further indicate hydrolysis benefit and viscosity benefits of
MauMan1. As a control substrate, an acid-pretreated whole
hydrolysate corn stover (whPCS) (see, e.g.,
www.nrel.gov/docs/fy11osti/47764.pdf), which does not contain any
GGM or GM, but contains .about.33.8 wt. % glucan, no xylan, and
.about.2.2 wt. % galactan, can be used.
[0310] An amount of 1.93 g of such a substrate (including, for
example the FPP-27 substrate or the SPORL-pretreated softwood
substrate, and the control whPCS substrate), at a dry solids
loading level of 8.6% and a total glucan loading of 7.0%, can then
be mixed with 10 mg/g glucan of Accellerase.RTM. TRIO.TM. as a
control mixture, and with 1 mg/g glucan of MauMan1 plus 9 mg/g
glucan of Accellerase.RTM. TRIO.TM. in a reaction mixture. The
reaction mixture and the control mixture are then adjusted to pH
5.0 using a 0.1 M sodium citrate buffer, and incubation can take
place with gentle agitation at a temperature of about 50.degree.
C., for at least 16 hours.
[0311] After at least 72 hours of incubation, the viscosity of each
of the resulting mixtures (about 1.2-1.75 grams of sample) can be
determined using the HR-1 rheometer (TA Instruments). A stainless
steel 40-mm parallel plate geometry is used. Viscosity evaluation
is performed at 23.degree. C. using a sweep shear rate from 50
second.sup.-1 to 1 second.sup.-1. The MauMan1 .beta.-mannanase
polypeptide, when mixed with Accellerase.RTM. TRIO.TM. in the
above-described proportions, imparts a substantial and clear
viscosity reduction benefit, such as, for example, achieving at
least a 20% reduced viscosity at the 72-hour incubation point as
compared to the when the control substrate whPCS is used.
[0312] Although the foregoing compositions and methods has been
described in some detail by way of illustration and example for
purposes of clarity of understanding, it is readily apparent to
those of ordinary skill in the art in light of the teachings herein
that certain changes and modifications may be made thereto without
departing from the spirit or scope of the appended claims.
[0313] Accordingly, the preceding merely illustrates the principles
of the present compositions and methods. It will be appreciated
that those skilled in the art will be able to devise various
arrangements which, although not explicitly described or shown
herein, embody the principles of the present compositions and
methods and are included within its spirit and scope. Furthermore,
all examples and conditional language recited herein are
principally intended to aid the reader in understanding the
principles of the present compositions and methods and the concepts
contributed by the inventors to furthering the art, and are to be
construed as being without limitation to such specifically recited
examples and conditions. Moreover, all statements herein reciting
principles, aspects, and embodiments of the present compositions
and methods as well as specific examples thereof, are intended to
encompass both structural and functional equivalents thereof.
Additionally, it is intended that such equivalents include both
currently known equivalents and equivalents developed in the
future, i.e., any elements developed that perform the same
function, regardless of structure. The scope of the present
compositions and methods, therefore, is not intended to be limited
to the exemplary embodiments shown and described herein.
Sequence CWU 1
1
3711539DNAMahella australiensis 1atgagcaaaa agaagatact ggcttttgcg
attgttatga tgttgattgt gtcattatta 60tgtggtactg tggtacactt gaatgaaact
aaagcggctc cttcgatcgc atctacaggt 120atagatgtga gcagtttaaa
aggggttaat catgcacata cctggtatcc agataggctg 180gttcaagctc
tgcaaggcat tcagtcatgg ggagccaatt ctgtgagagt tgtcttaagt
240aatggatgca agtgggcaaa aaatagtgct agtgatgtag caaatgtgat
atctaaagct 300caacagctcg gttttacagc agttatattg gaagtgcacg
atactacagg atatggagaa 360gacagctcag cttgttcgct taatgatgcc
gtagcctatt ggaaagaaat tcagagcgtt 420cttataggta aagaagactt
cgttataata aatataggta atgaaccata tggaaataat 480aattatcaaa
actggacaca ggatactatt gatgctatca atgcgttaag agaagcagga
540tttaatcata ctatcatggt agatgcaccg aactggggac aggattggtc
atttacaatg 600agggataatg ctccaaaggt atatgcagcg gatccgaata
aaaacatggt gttttctatc 660cacatgtatg gggtttataa cacggctcaa
aaagtgcatg attatttcca agcattcaaa 720gatatgaatt tacctctggt
agttggtgaa tttggaaacc agcattccga cggagatcct 780gatgaagaag
ctatagtgag ctatgcaaaa cagtatggta ttggatacct tggttggtca
840tggtgcggta atagcggtgg tgtggagtat ctcgatatgg taaataattg
ggatgcgaac 900agccctactt cttggggaaa ctggtttaaa accaatgctc
ttgcagaaat tacgccgccg 960tcggacacca caccacctgc agcacctaca
ggattgacgg ccacagccgt aagttcgagc 1020agcataaacc tcgattgggc
tgataatacg gacagcgacc tggccggata taaagtatac 1080agaagcacgt
tcagcggttt cacacctagt agcgccaact tcgcgaagca ggtaacaagc
1140agcgcttaca ccgatacggg cttgactgcc gatacaacgt attactataa
ggtgacggca 1200gtagatacca gcggcaatga atcacaacca tcggcacagg
ccagcgctaa aacacaacaa 1260ggtggaggta caacaccgcc gggagaatat
actgagatta ctttaccgtt tacccacgac 1320ggagcagggg aatattactg
gaagacaaat aaactttcca ctgatcccaa tgactggagc 1380cactatataa
actcgtggaa tctcgatctt cttgagatca acggaaaaaa ctacaccaat
1440gtatgggtgg cacaacacca gatagcacct ttgtcagacg gttactggta
tattcactgc 1500aaagggggtt tctcatactc tcatgtagag attaagtaa
15392512PRTMahella australiensis 2Met Ser Lys Lys Lys Ile Leu Ala
Phe Ala Ile Val Met Met Leu Ile 1 5 10 15 Val Ser Leu Leu Cys Gly
Thr Val Val His Leu Asn Glu Thr Lys Ala 20 25 30 Ala Pro Ser Ile
Ala Ser Thr Gly Ile Asp Val Ser Ser Leu Lys Gly 35 40 45 Val Asn
His Ala His Thr Trp Tyr Pro Asp Arg Leu Val Gln Ala Leu 50 55 60
Gln Gly Ile Gln Ser Trp Gly Ala Asn Ser Val Arg Val Val Leu Ser 65
70 75 80 Asn Gly Cys Lys Trp Ala Lys Asn Ser Ala Ser Asp Val Ala
Asn Val 85 90 95 Ile Ser Lys Ala Gln Gln Leu Gly Phe Thr Ala Val
Ile Leu Glu Val 100 105 110 His Asp Thr Thr Gly Tyr Gly Glu Asp Ser
Ser Ala Cys Ser Leu Asn 115 120 125 Asp Ala Val Ala Tyr Trp Lys Glu
Ile Gln Ser Val Leu Ile Gly Lys 130 135 140 Glu Asp Phe Val Ile Ile
Asn Ile Gly Asn Glu Pro Tyr Gly Asn Asn 145 150 155 160 Asn Tyr Gln
Asn Trp Thr Gln Asp Thr Ile Asp Ala Ile Asn Ala Leu 165 170 175 Arg
Glu Ala Gly Phe Asn His Thr Ile Met Val Asp Ala Pro Asn Trp 180 185
190 Gly Gln Asp Trp Ser Phe Thr Met Arg Asp Asn Ala Pro Lys Val Tyr
195 200 205 Ala Ala Asp Pro Asn Lys Asn Met Val Phe Ser Ile His Met
Tyr Gly 210 215 220 Val Tyr Asn Thr Ala Gln Lys Val His Asp Tyr Phe
Gln Ala Phe Lys 225 230 235 240 Asp Met Asn Leu Pro Leu Val Val Gly
Glu Phe Gly Asn Gln His Ser 245 250 255 Asp Gly Asp Pro Asp Glu Glu
Ala Ile Val Ser Tyr Ala Lys Gln Tyr 260 265 270 Gly Ile Gly Tyr Leu
Gly Trp Ser Trp Cys Gly Asn Ser Gly Gly Val 275 280 285 Glu Tyr Leu
Asp Met Val Asn Asn Trp Asp Ala Asn Ser Pro Thr Ser 290 295 300 Trp
Gly Asn Trp Phe Lys Thr Asn Ala Leu Ala Glu Ile Thr Pro Pro 305 310
315 320 Ser Asp Thr Thr Pro Pro Ala Ala Pro Thr Gly Leu Thr Ala Thr
Ala 325 330 335 Val Ser Ser Ser Ser Ile Asn Leu Asp Trp Ala Asp Asn
Thr Asp Ser 340 345 350 Asp Leu Ala Gly Tyr Lys Val Tyr Arg Ser Thr
Phe Ser Gly Phe Thr 355 360 365 Pro Ser Ser Ala Asn Phe Ala Lys Gln
Val Thr Ser Ser Ala Tyr Thr 370 375 380 Asp Thr Gly Leu Thr Ala Asp
Thr Thr Tyr Tyr Tyr Lys Val Thr Ala 385 390 395 400 Val Asp Thr Ser
Gly Asn Glu Ser Gln Pro Ser Ala Gln Ala Ser Ala 405 410 415 Lys Thr
Gln Gln Gly Gly Gly Thr Thr Pro Pro Gly Glu Tyr Thr Glu 420 425 430
Ile Thr Leu Pro Phe Thr His Asp Gly Ala Gly Glu Tyr Tyr Trp Lys 435
440 445 Thr Asn Lys Leu Ser Thr Asp Pro Asn Asp Trp Ser His Tyr Ile
Asn 450 455 460 Ser Trp Asn Leu Asp Leu Leu Glu Ile Asn Gly Lys Asn
Tyr Thr Asn 465 470 475 480 Val Trp Val Ala Gln His Gln Ile Ala Pro
Leu Ser Asp Gly Tyr Trp 485 490 495 Tyr Ile His Cys Lys Gly Gly Phe
Ser Tyr Ser His Val Glu Ile Lys 500 505 510 3485PRTMahella
australiensis 3Asn Glu Thr Lys Ala Ala Pro Ser Ile Ala Ser Thr Gly
Ile Asp Val 1 5 10 15 Ser Ser Leu Lys Gly Val Asn His Ala His Thr
Trp Tyr Pro Asp Arg 20 25 30 Leu Val Gln Ala Leu Gln Gly Ile Gln
Ser Trp Gly Ala Asn Ser Val 35 40 45 Arg Val Val Leu Ser Asn Gly
Cys Lys Trp Ala Lys Asn Ser Ala Ser 50 55 60 Asp Val Ala Asn Val
Ile Ser Lys Ala Gln Gln Leu Gly Phe Thr Ala 65 70 75 80 Val Ile Leu
Glu Val His Asp Thr Thr Gly Tyr Gly Glu Asp Ser Ser 85 90 95 Ala
Cys Ser Leu Asn Asp Ala Val Ala Tyr Trp Lys Glu Ile Gln Ser 100 105
110 Val Leu Ile Gly Lys Glu Asp Phe Val Ile Ile Asn Ile Gly Asn Glu
115 120 125 Pro Tyr Gly Asn Asn Asn Tyr Gln Asn Trp Thr Gln Asp Thr
Ile Asp 130 135 140 Ala Ile Asn Ala Leu Arg Glu Ala Gly Phe Asn His
Thr Ile Met Val 145 150 155 160 Asp Ala Pro Asn Trp Gly Gln Asp Trp
Ser Phe Thr Met Arg Asp Asn 165 170 175 Ala Pro Lys Val Tyr Ala Ala
Asp Pro Asn Lys Asn Met Val Phe Ser 180 185 190 Ile His Met Tyr Gly
Val Tyr Asn Thr Ala Gln Lys Val His Asp Tyr 195 200 205 Phe Gln Ala
Phe Lys Asp Met Asn Leu Pro Leu Val Val Gly Glu Phe 210 215 220 Gly
Asn Gln His Ser Asp Gly Asp Pro Asp Glu Glu Ala Ile Val Ser 225 230
235 240 Tyr Ala Lys Gln Tyr Gly Ile Gly Tyr Leu Gly Trp Ser Trp Cys
Gly 245 250 255 Asn Ser Gly Gly Val Glu Tyr Leu Asp Met Val Asn Asn
Trp Asp Ala 260 265 270 Asn Ser Pro Thr Ser Trp Gly Asn Trp Phe Lys
Thr Asn Ala Leu Ala 275 280 285 Glu Ile Thr Pro Pro Ser Asp Thr Thr
Pro Pro Ala Ala Pro Thr Gly 290 295 300 Leu Thr Ala Thr Ala Val Ser
Ser Ser Ser Ile Asn Leu Asp Trp Ala 305 310 315 320 Asp Asn Thr Asp
Ser Asp Leu Ala Gly Tyr Lys Val Tyr Arg Ser Thr 325 330 335 Phe Ser
Gly Phe Thr Pro Ser Ser Ala Asn Phe Ala Lys Gln Val Thr 340 345 350
Ser Ser Ala Tyr Thr Asp Thr Gly Leu Thr Ala Asp Thr Thr Tyr Tyr 355
360 365 Tyr Lys Val Thr Ala Val Asp Thr Ser Gly Asn Glu Ser Gln Pro
Ser 370 375 380 Ala Gln Ala Ser Ala Lys Thr Gln Gln Gly Gly Gly Thr
Thr Pro Pro 385 390 395 400 Gly Glu Tyr Thr Glu Ile Thr Leu Pro Phe
Thr His Asp Gly Ala Gly 405 410 415 Glu Tyr Tyr Trp Lys Thr Asn Lys
Leu Ser Thr Asp Pro Asn Asp Trp 420 425 430 Ser His Tyr Ile Asn Ser
Trp Asn Leu Asp Leu Leu Glu Ile Asn Gly 435 440 445 Lys Asn Tyr Thr
Asn Val Trp Val Ala Gln His Gln Ile Ala Pro Leu 450 455 460 Ser Asp
Gly Tyr Trp Tyr Ile His Cys Lys Gly Gly Phe Ser Tyr Ser 465 470 475
480 His Val Glu Ile Lys 485 4875PRTCaldicellulosiruptor
hydrothermalis 4Val Glu Thr Ser Val Gln Ser Tyr Val Phe Asp Phe Glu
Asp Gly Thr 1 5 10 15 Thr Met Thr Phe Asp Glu Ala Trp Gly Asp Ser
Leu Lys Cys Ile Lys 20 25 30 Lys Val Ser Val Ser Thr Asp Leu Gln
Arg Pro Gly Asn Lys Tyr Ala 35 40 45 Leu Arg Leu Asp Val Glu Phe
Asn Glu Asn Asn Gly Trp Asp Gln Gly 50 55 60 Asp Leu Gly Ala Trp
Ile Gly Gly Val Val Glu Gly Gln Phe Asp Phe 65 70 75 80 Thr Asn Tyr
Lys Ser Val Glu Phe Glu Met Phe Val Pro Tyr Asp Glu 85 90 95 Phe
Ala Lys Ala Lys Gly Gly Phe Ala Tyr Lys Val Val Leu Asn Asp 100 105
110 Gly Trp Lys Glu Leu Gly Ser Glu Phe Ser Ile Thr Val Asn Ala Gly
115 120 125 Lys Lys Val Lys Ile Asn Gly Lys Asp Tyr Met Val Ile His
Lys Ala 130 135 140 Phe Ala Ile Pro Asp Asp Phe Arg Thr Lys Lys Arg
Ala Gln Leu Val 145 150 155 160 Phe Gln Phe Ala Gly Gln Asn Cys Asn
Tyr Lys Gly Pro Ile Tyr Leu 165 170 175 Asp Asn Ile Arg Ile Arg Pro
Glu Asp Ala Ser Asn Leu Ser Lys Glu 180 185 190 Asp Tyr Gly Ser Ser
Glu Glu Glu Glu Ile Val Glu Asn Phe Phe Thr 195 200 205 Gly Val Thr
Leu Val Tyr Pro Val Glu Gly Lys Asn Phe Val Tyr Asn 210 215 220 Phe
Glu Lys Asp Thr Met Gly Phe Tyr Lys Tyr Ser Gly Asp Gly Phe 225 230
235 240 Ala Lys Lys Thr Lys Ser Met Glu Phe Ser Gln Asp Leu Lys Thr
Ser 245 250 255 Thr Asn Ala Gly Ser Leu Lys Leu Asn Ala Asn Phe Gln
Gly Thr Ala 260 265 270 Phe Glu Glu Met Asn Ile Ala Val Lys Leu Thr
Asp Lys Glu Gly Lys 275 280 285 Leu Phe Asp Leu Gly Lys Tyr Ser Thr
Leu Glu Tyr Thr Ile Tyr Ile 290 295 300 Pro Asn Pro Asp Lys Val Ala
Gly Lys Ile Met Ser Ala Ser Ala Val 305 310 315 320 Asp Ser Pro Trp
Lys Ile Ile Lys Asp Phe Thr Ala Leu Asn Tyr Lys 325 330 335 Asp Lys
Thr Thr Trp Lys Glu Ile Asn Gly Lys Thr Tyr Ala Val Ile 340 345 350
Lys Cys Lys Asp Asn Leu Tyr Asn Val Arg Glu Lys Ala Gly Val Leu 355
360 365 Val Leu Arg Ile Ala Gly Ser Tyr Val Lys Tyr Thr Gly Pro Ile
Tyr 370 375 380 Ile Asp Asn Val Ala Leu Ile Ala Gly Lys Lys Val Ala
Pro Lys Val 385 390 395 400 Glu Arg Ile Ser Leu Pro Asn Pro Lys Thr
Tyr Tyr Lys Val Lys Ile 405 410 415 Glu Ala Glu Ser Ala Ser Asp Gly
Trp Ala Tyr Ser Val Glu Lys Glu 420 425 430 Asn Ala Lys Phe Ser Gly
Lys Gly Tyr Val Leu Leu Phe Gly Asn Asn 435 440 445 Met Gly Asn Thr
Leu Tyr Asn Ile Lys Val Pro Lys Thr Gly His Tyr 450 455 460 Ile Phe
Thr Leu Ala Ile Ser Thr Leu Gly Leu Val Lys Asp Gly Ser 465 470 475
480 Ile Asp Ile Trp Ile Asp Gly Asp Leu Lys Gly Gly Ala Lys Val Pro
485 490 495 Asn Val Lys Gly Lys Phe Gln Glu Val Val Val Arg Lys Lys
Ile Tyr 500 505 510 Leu Thr Glu Gly Glu His Thr Ile Ser Leu Gln Lys
Ser Gly Gly Tyr 515 520 525 Thr Ile Ala Val Asp Tyr Phe Val Ile Glu
Glu Leu Val Ala Ala Asn 530 535 540 Lys Ser Lys Leu Ser Val Ser Ser
Lys Leu Val Thr Pro Asn Pro His 545 550 555 560 Pro Asn Ala Gln Arg
Leu Met Asn Tyr Leu Ala Ser Ile Tyr Gly Glu 565 570 575 Lys Ile Leu
Ser Gly Gln Gln Ser Ser Gly Glu Gly Lys Glu Val Gln 580 585 590 Met
Ile Phe Asp Val Thr Arg Arg Tyr Pro Ala Val Arg Ser Phe Asp 595 600
605 Leu Met Asp Tyr Ser Pro Ser Arg Met Gln Arg Gly Thr Lys Gly Thr
610 615 620 Asp Val Asp Glu Ala Ile Lys Trp Trp Lys Asn Gly Gly Ile
Val Ala 625 630 635 640 Phe Cys Trp His Trp Asn Ala Pro Thr Gly Leu
Ile Asp Gln Pro Gly 645 650 655 Lys Glu Trp Trp Arg Gly Phe Tyr Thr
Glu Ala Thr Thr Phe Asp Leu 660 665 670 Lys Lys Ala Met Asp Asn Pro
Asn Ser Glu Glu Tyr Lys Leu Ile Leu 675 680 685 Arg Asp Ile Asp Ala
Ile Ala Gln Gln Phe Lys Lys Leu Gln Ala Glu 690 695 700 Gly Val Pro
Val Leu Phe Arg Pro Leu His Glu Ala Ser Gly Gly Trp 705 710 715 720
Phe Trp Trp Gly Ala Lys Gly Ala Glu Pro Tyr Ile Lys Leu Trp Lys 725
730 735 Leu Met Phe Asp Arg Leu Val Asn Tyr His Lys Val Asn Asn Leu
Ile 740 745 750 Trp Val Trp Asn Gly Gln Asp Ala Ala Trp Tyr Pro Gly
Asp Gln Tyr 755 760 765 Val Asp Ile Ile Ala Glu Asp Ile Tyr Glu Glu
Lys Ala Gln Tyr Ser 770 775 780 Pro Tyr Thr Glu Arg Phe Val Lys Ala
Leu Lys Tyr Thr Asn Ser Asn 785 790 795 800 Lys Met Ile Ala Leu Ser
Glu Cys Gly Thr Ile Pro Asp Pro Ala Val 805 810 815 Leu Lys Gln Glu
Gly Val Ser Trp Leu Trp Phe Ser Val Trp Ala Gly 820 825 830 Gly Tyr
Val Met Thr Gly Ser Lys Tyr Asn Asp Glu Trp Asn Asp Asn 835 840 845
His Met Leu Arg Lys Ile Tyr Asn Ser Asp Tyr Val Ile Thr Lys Asp 850
855 860 Glu Leu Pro Asp Ile Lys Ser Ile Pro Leu Glu 865 870 875
5424PRTThermobifida cellulosilytica 5Ala Thr Gly Ile His Val Arg
Asn Gly Arg Ile Tyr Glu Ala Asn Gly 1 5 10 15 Gln Glu Phe Val Met
Arg Gly Val Ser His Ala His Thr Trp Tyr Pro 20 25 30 Gln His Thr
Arg Ala Phe Ala Asp Ile Lys Ser His Gly Ala Asn Thr 35 40 45 Val
Arg Val Val Leu Ser Asn Gly Val Arg Trp Ser Lys Asn Gly Pro 50 55
60 Ser Asp Val Ala Asp Ile Ile Ser Leu Cys Lys Gln Asn Arg Leu Ile
65 70 75 80 Cys Met Leu Glu Val His Asp Thr Thr Gly Tyr Gly Glu Gln
Ser Gly 85 90 95 Ala Ala Thr Leu Asp Gln Ala Val Asp Tyr Trp Ile
Glu Leu Lys Ser 100 105 110 Val Leu Gln Gly Gln Glu Asp Tyr Val Leu
Ile Asn Ile Gly Asn Glu 115 120 125 Pro Tyr Gly Asn Asn Ala Ala Thr
Val Ala Asn Trp Ala Ser Asp Thr 130 135 140 Ser Ala Ala Ile Arg Arg
Leu Arg Ala Ala Gly Phe Glu His Ala Ile 145 150 155 160 Val Val Asp
Ala Pro Asn Trp Gly Gln Asp Trp Ser His Thr Met Arg
165 170 175 Thr Asn Ala Ala Asp Val Tyr Ala Ser Asp Pro Thr Gly Asn
Thr Ile 180 185 190 Phe Ser Ile His Met Tyr Gly Val Tyr Ser Gln Gly
Ser Thr Val Thr 195 200 205 Ser Tyr Leu Glu His Phe Val Asn Ala Gly
Leu Pro Leu Val Ile Gly 210 215 220 Glu Phe Gly His Asp His Ser Asp
Gly Asn Pro Asp Glu Asp Thr Ile 225 230 235 240 Met Ala Glu Ala Glu
Arg Leu Gly Leu Gly Tyr Ile Gly Trp Ser Trp 245 250 255 Ser Gly Asn
Gly Gly Gly Val Glu Tyr Leu Asp Met Val Asp Asn Phe 260 265 270 Asp
Gly Asp Ser Leu Thr Ser Trp Gly Arg Arg Ile Phe Tyr Gly Pro 275 280
285 Asn Gly Ile Ser Gly Thr Ala Arg Glu Ala Thr Val Tyr Ser Gly Asp
290 295 300 Pro Gly Thr Asp Pro Gly Thr Asp Pro Gly Thr Asp Pro Gly
Thr Asp 305 310 315 320 Pro Gly Thr Asp Pro Gly Thr Gly Ala Cys Ser
Ala Ala Tyr Thr Thr 325 330 335 Val Gly Asp Trp Gly Ser Gly Phe Gln
Gly Glu Val Thr Val Thr Ala 340 345 350 Gly Ser Ser Ala Ile Ser His
Trp Lys Val Thr Trp Thr Phe Pro Gly 355 360 365 Gly Gln Ser Val Ser
His Gly Trp Asn Ala Ala Phe Asn Gly Ser Ser 370 375 380 Ser Val Thr
Ala Thr Ser Leu Ser Tyr Asn Gly Gln Leu Gly Ala Gly 385 390 395 400
Gln Ser Thr Ala Phe Gly Phe Ile Gly Ser Gly Ser Ala Pro Gly Ala 405
410 415 Leu Thr Leu Thr Cys Ser Val Asp 420 61551DNAartificial
sequencesynthetic construct 6gtgagaagca aaaaattgtg gatcagcttg
ttgtttgcgt taacgttaat ctttacgatg 60gcgttcagca acatgagcgc gcaggctgct
ggaaaaaacg aaacaaaagc agcaccgtca 120attgcatcaa caggcattga
tgtttcatca ctgaaaggcg ttaatcatgc gcatacatgg 180tatccggatc
gcctggttca agcactgcaa ggcattcaaa gctggggagc aaattcagtt
240agagttgttc tgtcaaatgg ctgcaaatgg gcaaaaaatt cagcatcaga
tgtcgcgaat 300gttattagca aagcacaaca actgggcttt acagcagtta
ttctggaagt tcatgataca 360acaggctatg gcgaagattc atcagcatgc
tcactgaatg atgcagttgc atattggaaa 420gaaattcagt cagtcctgat
cggcaaagaa gattttgtca ttattaacat cggcaacgaa 480ccgtatggca
acaataacta tcaaaactgg acacaggata cgatcgatgc aattaatgca
540ctgagagaag caggctttaa ccatacaatt atggttgatg caccgaattg
gggacaagat 600tggtcattta caatgagaga taatgctccg aaagtctatg
cagcagatcc gaataaaaac 660atggtcttta gcatccatat gtatggcgtc
tataatacag cgcagaaagt ccatgattac 720tttcaggcgt ttaaagatat
gaatctgccg ctggttgttg gcgaatttgg caatcaacat 780tcagatggcg
atcctgatga agaggcaatt gtttcatatg cgaaacaata tggcattggc
840tatctgggct ggtcatggtg cggcaattca ggcggagttg aatatctgga
tatggtcaat 900aattgggatg caaatagccc gacatcatgg ggcaattggt
ttaaaacaaa tgcactggca 960gaaattacac cgcctagcga tacaacaccg
cctgcagcac cgacaggcct gacagcaaca 1020gcagtttcat catcatcaat
taatctggat tgggcagata acacagattc agatctggca 1080ggctataaag
tctatagatc aacattttca ggctttacac cgagcagcgc aaattttgct
1140aaacaagtta caagcagcgc gtatacagat acaggactta cagcagatac
gacgtattat 1200tacaaagtta cagcggttga tacgagcggc aatgaatcac
aaccgtcagc acaagcatca 1260gcaaaaacac aacaaggcgg aggcacaaca
cctccgggtg aatatacaga aatcacactg 1320ccgtttacac atgatggcgc
aggcgaatac tattggaaaa caaataaact gagcacggat 1380ccgaatgatt
ggagccatta tatcaatagc tggaacctgg atctgcttga aattaacggc
1440aaaaactata caaatgtctg ggtcgcgcaa catcaaattg caccgctgtc
agatggctat 1500tggtatattc attgcaaagg cggatttagc tatagccacg
tcgaaatcaa a 15517517PRTartificial sequenceprotein expressed from
synthetic construct 7Met Arg Ser Lys Lys Leu Trp Ile Ser Leu Leu
Phe Ala Leu Thr Leu 1 5 10 15 Ile Phe Thr Met Ala Phe Ser Asn Met
Ser Ala Gln Ala Ala Gly Lys 20 25 30 Asn Glu Thr Lys Ala Ala Pro
Ser Ile Ala Ser Thr Gly Ile Asp Val 35 40 45 Ser Ser Leu Lys Gly
Val Asn His Ala His Thr Trp Tyr Pro Asp Arg 50 55 60 Leu Val Gln
Ala Leu Gln Gly Ile Gln Ser Trp Gly Ala Asn Ser Val 65 70 75 80 Arg
Val Val Leu Ser Asn Gly Cys Lys Trp Ala Lys Asn Ser Ala Ser 85 90
95 Asp Val Ala Asn Val Ile Ser Lys Ala Gln Gln Leu Gly Phe Thr Ala
100 105 110 Val Ile Leu Glu Val His Asp Thr Thr Gly Tyr Gly Glu Asp
Ser Ser 115 120 125 Ala Cys Ser Leu Asn Asp Ala Val Ala Tyr Trp Lys
Glu Ile Gln Ser 130 135 140 Val Leu Ile Gly Lys Glu Asp Phe Val Ile
Ile Asn Ile Gly Asn Glu 145 150 155 160 Pro Tyr Gly Asn Asn Asn Tyr
Gln Asn Trp Thr Gln Asp Thr Ile Asp 165 170 175 Ala Ile Asn Ala Leu
Arg Glu Ala Gly Phe Asn His Thr Ile Met Val 180 185 190 Asp Ala Pro
Asn Trp Gly Gln Asp Trp Ser Phe Thr Met Arg Asp Asn 195 200 205 Ala
Pro Lys Val Tyr Ala Ala Asp Pro Asn Lys Asn Met Val Phe Ser 210 215
220 Ile His Met Tyr Gly Val Tyr Asn Thr Ala Gln Lys Val His Asp Tyr
225 230 235 240 Phe Gln Ala Phe Lys Asp Met Asn Leu Pro Leu Val Val
Gly Glu Phe 245 250 255 Gly Asn Gln His Ser Asp Gly Asp Pro Asp Glu
Glu Ala Ile Val Ser 260 265 270 Tyr Ala Lys Gln Tyr Gly Ile Gly Tyr
Leu Gly Trp Ser Trp Cys Gly 275 280 285 Asn Ser Gly Gly Val Glu Tyr
Leu Asp Met Val Asn Asn Trp Asp Ala 290 295 300 Asn Ser Pro Thr Ser
Trp Gly Asn Trp Phe Lys Thr Asn Ala Leu Ala 305 310 315 320 Glu Ile
Thr Pro Pro Ser Asp Thr Thr Pro Pro Ala Ala Pro Thr Gly 325 330 335
Leu Thr Ala Thr Ala Val Ser Ser Ser Ser Ile Asn Leu Asp Trp Ala 340
345 350 Asp Asn Thr Asp Ser Asp Leu Ala Gly Tyr Lys Val Tyr Arg Ser
Thr 355 360 365 Phe Ser Gly Phe Thr Pro Ser Ser Ala Asn Phe Ala Lys
Gln Val Thr 370 375 380 Ser Ser Ala Tyr Thr Asp Thr Gly Leu Thr Ala
Asp Thr Thr Tyr Tyr 385 390 395 400 Tyr Lys Val Thr Ala Val Asp Thr
Ser Gly Asn Glu Ser Gln Pro Ser 405 410 415 Ala Gln Ala Ser Ala Lys
Thr Gln Gln Gly Gly Gly Thr Thr Pro Pro 420 425 430 Gly Glu Tyr Thr
Glu Ile Thr Leu Pro Phe Thr His Asp Gly Ala Gly 435 440 445 Glu Tyr
Tyr Trp Lys Thr Asn Lys Leu Ser Thr Asp Pro Asn Asp Trp 450 455 460
Ser His Tyr Ile Asn Ser Trp Asn Leu Asp Leu Leu Glu Ile Asn Gly 465
470 475 480 Lys Asn Tyr Thr Asn Val Trp Val Ala Gln His Gln Ile Ala
Pro Leu 485 490 495 Ser Asp Gly Tyr Trp Tyr Ile His Cys Lys Gly Gly
Phe Ser Tyr Ser 500 505 510 His Val Glu Ile Lys 515
8488PRTartificial sequenceprotein expressed from synthetic
construct 8Ala Gly Lys Asn Glu Thr Lys Ala Ala Pro Ser Ile Ala Ser
Thr Gly 1 5 10 15 Ile Asp Val Ser Ser Leu Lys Gly Val Asn His Ala
His Thr Trp Tyr 20 25 30 Pro Asp Arg Leu Val Gln Ala Leu Gln Gly
Ile Gln Ser Trp Gly Ala 35 40 45 Asn Ser Val Arg Val Val Leu Ser
Asn Gly Cys Lys Trp Ala Lys Asn 50 55 60 Ser Ala Ser Asp Val Ala
Asn Val Ile Ser Lys Ala Gln Gln Leu Gly 65 70 75 80 Phe Thr Ala Val
Ile Leu Glu Val His Asp Thr Thr Gly Tyr Gly Glu 85 90 95 Asp Ser
Ser Ala Cys Ser Leu Asn Asp Ala Val Ala Tyr Trp Lys Glu 100 105 110
Ile Gln Ser Val Leu Ile Gly Lys Glu Asp Phe Val Ile Ile Asn Ile 115
120 125 Gly Asn Glu Pro Tyr Gly Asn Asn Asn Tyr Gln Asn Trp Thr Gln
Asp 130 135 140 Thr Ile Asp Ala Ile Asn Ala Leu Arg Glu Ala Gly Phe
Asn His Thr 145 150 155 160 Ile Met Val Asp Ala Pro Asn Trp Gly Gln
Asp Trp Ser Phe Thr Met 165 170 175 Arg Asp Asn Ala Pro Lys Val Tyr
Ala Ala Asp Pro Asn Lys Asn Met 180 185 190 Val Phe Ser Ile His Met
Tyr Gly Val Tyr Asn Thr Ala Gln Lys Val 195 200 205 His Asp Tyr Phe
Gln Ala Phe Lys Asp Met Asn Leu Pro Leu Val Val 210 215 220 Gly Glu
Phe Gly Asn Gln His Ser Asp Gly Asp Pro Asp Glu Glu Ala 225 230 235
240 Ile Val Ser Tyr Ala Lys Gln Tyr Gly Ile Gly Tyr Leu Gly Trp Ser
245 250 255 Trp Cys Gly Asn Ser Gly Gly Val Glu Tyr Leu Asp Met Val
Asn Asn 260 265 270 Trp Asp Ala Asn Ser Pro Thr Ser Trp Gly Asn Trp
Phe Lys Thr Asn 275 280 285 Ala Leu Ala Glu Ile Thr Pro Pro Ser Asp
Thr Thr Pro Pro Ala Ala 290 295 300 Pro Thr Gly Leu Thr Ala Thr Ala
Val Ser Ser Ser Ser Ile Asn Leu 305 310 315 320 Asp Trp Ala Asp Asn
Thr Asp Ser Asp Leu Ala Gly Tyr Lys Val Tyr 325 330 335 Arg Ser Thr
Phe Ser Gly Phe Thr Pro Ser Ser Ala Asn Phe Ala Lys 340 345 350 Gln
Val Thr Ser Ser Ala Tyr Thr Asp Thr Gly Leu Thr Ala Asp Thr 355 360
365 Thr Tyr Tyr Tyr Lys Val Thr Ala Val Asp Thr Ser Gly Asn Glu Ser
370 375 380 Gln Pro Ser Ala Gln Ala Ser Ala Lys Thr Gln Gln Gly Gly
Gly Thr 385 390 395 400 Thr Pro Pro Gly Glu Tyr Thr Glu Ile Thr Leu
Pro Phe Thr His Asp 405 410 415 Gly Ala Gly Glu Tyr Tyr Trp Lys Thr
Asn Lys Leu Ser Thr Asp Pro 420 425 430 Asn Asp Trp Ser His Tyr Ile
Asn Ser Trp Asn Leu Asp Leu Leu Glu 435 440 445 Ile Asn Gly Lys Asn
Tyr Thr Asn Val Trp Val Ala Gln His Gln Ile 450 455 460 Ala Pro Leu
Ser Asp Gly Tyr Trp Tyr Ile His Cys Lys Gly Gly Phe 465 470 475 480
Ser Tyr Ser His Val Glu Ile Lys 485 929PRTBacillus subtilis 9Met
Arg Ser Lys Lys Leu Trp Ile Ser Leu Leu Phe Ala Leu Thr Leu 1 5 10
15 Ile Phe Thr Met Ala Phe Ser Asn Met Ser Ala Gln Ala 20 25
1032PRTTrichoderma reesei 10Met Val Ser Phe Thr Ser Leu Leu Ala Ala
Ser Pro Pro Ser Arg Ala 1 5 10 15 Ser Cys Arg Pro Ala Ala Glu Val
Glu Ser Val Ala Val Glu Lys Arg 20 25 30 1116PRTTrichoderma reesei
11Met Lys Ala Asn Val Ile Leu Cys Leu Leu Ala Pro Leu Val Ala Ala 1
5 10 15 1219PRTTrichoderma reesei 12Met Arg Tyr Arg Thr Ala Ala Ala
Leu Ala Leu Ala Thr Gly Pro Phe 1 5 10 15 Ala Arg Ala
1318PRTTrichoderma reesei 13Met Ile Val Gly Ile Leu Thr Thr Leu Ala
Thr Leu Ala Thr Leu Ala 1 5 10 15 Ala Ser 1417PRTTrichoderma reesei
14Met Tyr Arg Lys Leu Ala Val Ile Ser Ala Phe Leu Ala Thr Ala Arg 1
5 10 15 Ala 1523PRTFusarium verticillioides 15Met Leu Leu Asn Leu
Gln Val Ala Ala Ser Ala Leu Ser Leu Ser Leu 1 5 10 15 Leu Gly Gly
Leu Ala Glu Ala 20 1619PRTFusarium verticillioides 16Met Lys Leu
Asn Trp Val Ala Ala Ala Leu Ser Ile Gly Ala Ala Gly 1 5 10 15 Thr
Asp Ser 1719PRTFusarium verticillioides 17Met Ala Ser Ile Arg Ser
Val Leu Val Ser Gly Leu Leu Ala Ala Gly 1 5 10 15 Val Asn Ala
1822PRTFusarium verticillioides 18Met Trp Leu Thr Ser Pro Leu Leu
Phe Ala Ser Thr Leu Leu Gly Leu 1 5 10 15 Thr Gly Val Ala Leu Ala
20 1916PRTFusarium verticillioides 19Met Arg Phe Ser Trp Leu Leu
Cys Pro Leu Leu Ala Met Gly Ser Ala 1 5 10 15 2022PRTFusarium
verticillioides 20Met Arg Leu Leu Ser Phe Pro Ser His Leu Leu Val
Ala Phe Leu Thr 1 5 10 15 Leu Lys Glu Ala Ser Ser 20
2120PRTFusarium verticillioides 21Met Gln Leu Lys Phe Leu Ser Ser
Ala Leu Leu Leu Ser Leu Thr Gly 1 5 10 15 Asn Cys Ala Ala 20
2218PRTFusarium verticillioides 22Met Lys Val Tyr Trp Leu Val Ala
Trp Ala Thr Ser Leu Thr Pro Ala 1 5 10 15 Leu Ala 2319PRTFusarium
verticillioides 23Met Val Arg Phe Ser Ser Ile Leu Ala Ala Ala Ala
Cys Phe Val Ala 1 5 10 15 Val Glu Ser 2420PRTPodospora anserine
24Met Ile His Leu Lys Pro Ala Leu Ala Ala Leu Leu Ala Leu Ser Thr 1
5 10 15 Gln Cys Val Ala 20 2517PRTPodospora anserine 25Met Ala Leu
Gln Thr Phe Phe Leu Leu Ala Ala Ala Met Leu Ala Asn 1 5 10 15 Ala
2619PRTPodospora anserine 26Met Lys Leu Asn Lys Pro Phe Leu Ala Ile
Tyr Leu Ala Phe Asn Leu 1 5 10 15 Ala Glu Ala 2720PRTChaetomium
globosum 27Met Ala Pro Leu Ser Leu Arg Ala Leu Ser Leu Leu Ala Leu
Thr Gly 1 5 10 15 Ala Ala Ala Ala 20 2819PRTThermoascus aurantiacus
28Met Val Arg Pro Thr Ile Leu Leu Thr Ser Leu Leu Leu Ala Pro Phe 1
5 10 15 Ala Ala Ala 2921PRTAspergillus terreus 29Met His Met His
Ser Leu Val Ala Ala Leu Ala Ala Gly Thr Leu Pro 1 5 10 15 Leu Leu
Ala Ser Ala 20 3019PRTAspergillus fumigatus 30Met Val His Leu Ser
Ser Leu Ala Ala Ala Leu Ala Ala Leu Pro Leu 1 5 10 15 Val Tyr Gly
3117PRTAspergillus fumigatus 31Met Arg Phe Ser Leu Ala Ala Thr Thr
Leu Leu Ala Gly Leu Ala Thr 1 5 10 15 Ala 3219PRTAspergillus
fumigatus 32Met Val Val Leu Ser Lys Leu Val Ser Ser Ile Leu Phe Ala
Ser Leu 1 5 10 15 Val Ser Ala 3319PRTAspergillus kawachii 33Met Val
Gln Ile Lys Ala Ala Ala Leu Ala Met Leu Phe Ala Ser His 1 5 10 15
Val Leu Ser 3417PRTMagnaporthe grisea 34Met Lys Ala Ser Ser Val Leu
Leu Gly Leu Ala Pro Leu Ala Ala Leu 1 5 10 15 Ala
3519PRTSaccharomyces cerevisiae 35Met Arg Phe Pro Ser Ile Phe Thr
Ala Val Leu Phe Ala Ala Ser Ser 1 5 10 15 Ala Leu Ala
3685PRTSaccharomyces cerevisiae 36Met Arg Phe Pro Ser Ile Phe Thr
Ala Val Leu Phe Ala Ala Ser Ser 1 5 10 15 Ala Leu Ala Ala Pro Val
Asn Thr Thr Thr Glu Asp Glu Thr Ala Gln 20 25 30 Ile Pro Ala Glu
Ala Val Ile Gly Tyr Leu Asp Leu Glu Gly Asp Phe 35 40 45 Asp Val
Ala Val Leu Pro Phe Ser Asn Ser Thr Asn Asn Gly Leu Leu 50 55 60
Phe Ile Asn Thr Thr Ile Ala Ser Ile Ala Ala Lys Glu Glu Gly Val 65
70 75 80 Ser Leu Asp Lys Arg 85 3720PRTSaccharomyces cerevisiae
37Met Leu Leu Gln Ala Phe Leu Phe Leu Leu Ala Gly Phe Ala Ala Lys 1
5 10 15 Ile Ser Ala Arg 20
* * * * *
References